charge controler mppt bluesolar 150/70?

javadzjavadz Registered Users Posts: 20
hello
please can someone explain me if the solar charge controller Victron Bluesolar Mppt 150/70 protect battery from discharge and overload?
because when i read the datasheet i didn't found anything on that.
it says that it can charge the battery with maximum power from panel but did it protect battery?
now suppose i have this system ,panels ,blue solar 150/70 charge controller,battery and an inverter connected to battery, how i can protect the battery from overload and surcharge
Thank you?
«1

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?

    According to a quick look at their website:

    http://www.victronenergy.com/solar-charge-controllers/mppt15070/#type-1

    The larger units do not have a separate LOAD control/output.

    And that is pretty normal. Most smaller charge controllers with load outputs are only good for ~7 to 30 amps or so... And for larger systems, a good sized inverter can draw 100-200 amps or more--Very costly and, relatively, unneeded circuitry for a larger solar charge controller.

    It appears that Victron does have an integrated communications network which can program a compatible Inverter to load shed (and shut down?) if battery voltage is low.

    http://www.victronenergy.com/upload/documents/Datasheet-Blue-Solar-Charge-Controller-overview-EN.pdf

    Over discharging a battery bank can be very hard on them (if you take them below 50% state of charge very often), or even kill the (expensive bank) if you take them below ~20% state of charge.

    Automation to control/protect your battery bank system is always problematic--If you are there when the system is running, then your normal monitoring of the battery voltage, and Battery Monitor (Victron makes a nice product)--It is usually good enough.

    If you need to have the system run automatically when you are not there (run refrigerator, freezer, security system, pumps, etc.)--Many times the automation can cause its own problems (for example, if the system shuts down when the battery is below 50%, will it automatically restart or will it require manual intervention).

    In general, you are always playing a balancing act between Loads, Sun, and backup power (generator, etc.)... Successful automation of all of these components can be done--But it may be costly, and run into issues. Keeping a system "simple" and small (conservation of energy) can also be a good solution too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: charge controler mppt bluesolar 150/70?

    I am not familiar wit the model but Victron generally has a good reputation.
    As to your question, the answer is : You have to set the charge controller up to charge the batteries to the battery manufacturers specifications for voltage and amperage, if the CC will allow you to do that.

    Good CC's allow for battery specific settings... If you can afford it , get a good CC.
    Just scanned BB's comments.... sounds like the model is a very basic one, you should compare it to the MidNite KID http://www.midnitesolar.com/pages/kid/index.php
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?

    I don't think the Victron unit is "basic"... It sounds very much like an Outback or Schneider/Xantrex high end MPPT controller. But, I do not know much of anything about them either.

    It is just that the Victron charge controller "family" does cross from small to large units, with changing design configurations over the range of units.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: charge controler mppt bluesolar 150/70?

    Right Bill, I looked at their inverters a while back and they have different lines that include the same Watt output sizes but are completely different animals... makes it hard to know just which line to choose let alone size.. Low tare rates though...


    That 150/70 sounds like it is the class of an old MX60...150V, 70A
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?

    thank you all for your respnse
    but i am little confuse
    i want to made a stand alone pv systeme
    i have panels (2000w),a blue solar charge controler blue solar mppt150/70,battery (48v),and an inverter, and i want to power (say 20 lamps) from the inverter
    i connect the inverter to the battery,(sinc the blue solar charge controler do not have a load outpout),
    so if the system run ,the charge controler will charge the battery to 100% all the day but when the battery are at 56.6V (for 48v system) that mean that the battery are charged ,does the charge controler stope charging the battery in this case or continue to charge it ,because if it continue to charge the battery that means that we have problem of surcharge
    second for this systeme ,is it a good idea to charge and disharge the battery every day since the lamps will take the power from the inverter that is vonnected to the battery?
    sorry for all this questions
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: charge controler mppt bluesolar 150/70?

    The charge controller does just that: regulates the charging of the batteries from the solar panels. It will not allow the batteries to be overcharged, providing the settings match the batteries' requirements.

    It does not have the ability to limit discharge of the batteries through the inverter (or other DC loads). The inverter should have a Low Voltage Disconnect setting to prevent that from happening. On many inverters this is a fixed value, and may be too low to be of practical use.

    Nor will the charge controller prevent overcharging from any source other than the PV such as a charger built in to the inverter or other stand alone AC powered charger.

    Fuses or circuit breakers should be used on both the circuit from the charge controller to the batteries and from the batteries to the inverter to prevent excess current in the wires from starting a fire.
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?
    javadz wrote: »
    thank you all for your respnse
    but i am little confuse
    i want to made a stand alone pv system.
    Yes, you are correct. The system you are looking at does allow you to make a stand alone off grid power system that can supply AC power (230 VAC at 50 Hz for Algiers, Algeria?).

    I am not familiar with Victron equipment/systems. Their details for connecting of their shared data bus between charge controller, AC inverter (I am in the US, and not a solar power systems installer)--But the basics are as you think.

    The solar panels connect to the solar charge controller which ensures the battery bank is not over charged. The charge controller "turns on" when the sun is shining on the solar panels and "turns off" when the battery bank is fully charged.

    There are two major types of solar charge controllers. One is a "PWM" (Pulse Width Modulation). More or less, it controls battery charging current by turning "on and off" very quickly (ON for 1/10th second, OFF for 1/10th second is 50% average charging current. ON for 1/100 second, OFF for 99/100 second, then only 1% of available charging current).

    The other major class is MPPT (Maximum Power Point Tracking). This is the type the Victron brand/model of charge controller you are looking at is. It contains a "switch mode digital power supply" inside. Basically, it can behave like a DC version of an AC Transformer. It can take "high voltage/low current" and "down convert" to "low current/high voltage" needed to charge the battery bank.

    For example, this allows you to put three large solar panels in series (say 10 amps Imp (current maximum power) and 30 volts Vmp (voltage maximum power) example with a 300 Watt solar panel) and down convert to 58 volts needed to charge the battery bank:

    3 panels in series * 30 volts Vmp = 90 Volts Vmp-array
    90 volts Vmp * 10 amps Imp = 900 Watt solar array
    900 Watt solar array / 58 volts battery charging = 15.5 Amps battery charging current

    So, 10 amps in from the solar array becomes ~15.5 Amps at the battery bank. This is not "free energy". Power=Volts*Current (P=I*V). So with an MPPT controller, you can run the solar array at a high voltage and efficiently down convert to lower voltage/higher current needed by the battery bank. This allows you to use smaller diameter wire and/or longer wire runs from the solar array to the battery bank.

    Note that Lead Acid flooded cell storage batteries are relatively good at storing electricity--They do have their requirements for charging current/voltage and time. You should read about the care of a lead acid battery bank (and you need to tell us what type of batteries you have--The major types used with solar power systems are flooded cell and AGM (Absorbed Glass Mat, Valve Regulated--"Sealed").

    You need to read about the care and use of Storage Batteries to understand how best to maintain them. With batteries in automobiles and trucks, we tend to "forget about them". For Off Grid power systems, you need to understand and monitor them pretty closely. It is easy to over discharge them, over charge them, forget to add water, etc. and ruin your very expensive battery bank in days/weeks/months, instead of getting the 5-15 years of life you want.

    Here are some links to Battery Information in English--And you can probably find similar in Arabic or other language(s) that you may be more familiar with (I only know English, poorly--So I am always impressed by people who visit this forum and hold very technical discussions not in their native language).

    http://www.windsun.com/Batteries/Battery_FAQ.htm
    http://www.batteryfaq.org/
    http://batteryuniversity.com/

    And, the other 1/2 of the system, connecting a battery bank to your AC inverter. Takes ~41-60 VDC power in and converts it to 230 VAC 50 Hz power out.

    The battery bank is for storing energy (electrical power) gathered by the solar array and supplying it to the AC inverter when the sun has set, or if you need power during the day, it will take power from the solar array and/or battery bank as needed.

    A basic solar power system is very much like your car's electrical system. The battery is the "heart" of the system. When the engine is stopped, the battery supplies energy to the lights/radio/etc.. When the engine is running, the alternator (or generator) will recharge the battery and supply other other loads.

    i have panels (2000w),a blue solar charge controller blue solar mppt150/70,battery (48v),and an inverter, and i want to power (say 20 lamps) from the inverter.

    Yes, that is all of is correct. Now we get into details of your "paper design" (don't buy any parts, batteries, etc. yet until you have a paper design--It is very difficult to buy "random" solar power parts and put them together in a cost effective/reliable power system.

    So--First thing to do is to measure/estimate your power needs. 20 Lamps does not tell us much. We need to know their working voltage (230 VAC), their current (say 1 amp per Lamp * 20 lamps), and how many hours per day you will run those lamps (say 5 hours per night).
    • 230 VAC * 1 amp = 230 Watts of lamp
    • 20 lamps * 230 Watts = 4,600 Watts of lamps
    • 4,600 Watts of lamps * 5 hours of run time per evening = 23,000 Watt*Hours of energy per night
    The above is just an example, and for an off grid power system, that is a LOT OF POWER (Energy) used per night, and would be a very expensive system to build. A lot of solar panels, a very large battery bank, and relatively large AC inverter. It would be too expensive for almost anyone to build (other than very wealthy, for a business, etc.).

    However, with solar power, we have many new devices that we can use instead of "old technology" to allow us to save energy/electricity. And for off grid solar power, doing anything we can to save electricity is usually worth the time/money. It is almost always cheaper to conserve power than to generate power.

    For example, instead of using 230 Watt filament lamps (traditional light bulbs), you can get LED type bulbs (with reflectors, if needed) to direct light to where you need it at about 1/10th the amount of Watts (power) (LED lights are ~10x more expensive to purchase).

    Now each bulb may use 0.1 amp, and the battery bank+solar array+AC inverter can all be 1/10 the size. Which now is a very reasonable size off grid power system (in my imaginary system design).

    There are simple 'Watt*Hour' meters you can plug your appliances into and measure their power usage. Here is an example. You should be able to find WattHour meters locally (this is a United Kingdom/England version):

    http://www.amazon.co.uk/Plug-In-Power-and-Energy-Monitor/dp/B000Q7PJGW

    More or less, to give you an idea:
    • 1,000 WH per day (1 kWH) is a "small" system that can give you lights, radio, laptop computer, small water pump
    • 3,300 WH per day (3.3 kWH) is a "good size" system... Add refrigerator, larger well pump, clothes washing machine, etc. Pretty much would give a very energy efficient home a "modern" off grid electrical system experience (use propane, oil, petrol for heating/cooking)
    • 10 kWH per day (300 kWH per month) is would power a reasonably efficient home with some electricity for cooking, some more fans/small amount of air conditioning, etc.
    • 33 kWH per day (1,000 kWH per month) is the average power usage for a North American or European home (electric cooking, some electric hot water/heating, more computers, refrigerators, lights left on, etc.). Most people that have never worked at conservation could probably cut their electrical usage by 1/2 with conservation (new technology lighting, appliances, converting to propane for cooking/heating).
    • 100 kWH per day (3,000 kWH per month) for homes in very hot/very cold climates that use lots of electrical heat and air conditioning.
    More or less, only the 1-3.3 kWH per day systems are "comfortable" for most people. And small enough/"simple" enough for people to install the system their selves.

    The 10 kWH per day system is possible and possibly cost effective for a full off grid home/business, but that is about the largest system we would be able to help with here. (of course, we want you to be educated about solar power so you can understand the basic elements when you have discussions with a solar power company).

    Larger systems are usually too expensive for most people and most people would need to use a company/person with lots of experience with off grid power. The issues are too complex for a first time solar person with no electrical engineering experience.

    End of Part 1
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?

    Begin Part 2:

    i connect the inverter to the battery,(since the blue solar charge controller do not have a load output), so if the system run ,the charge controller will charge the battery to 100% all the day but when the battery are at 56.6V (for 48v system) that mean that the battery are charged ,does the charge controller stop charging the battery in this case or continue to charge it, because if it continue to charge the battery that means that we have problem of surcharge

    Note that we say "over charge" vs "surcharge" (surcharge is like a sales tax or extra fee for long distance shipping charges):
    sur-
    Word Origin: a prefix meaning “over, above,” “in addition,” occurring mainly in loanwords from French and partial calques of French words: surcharge; surname; surrender; survive.

    Your English is very good and readable--Just wanted to correct a term.

    Solar panels are, sort of, variable output Solar Batteries (actually a variable current source based on the amount of sun hitting the panels--But save that for a different discussion).

    The solar charge controller monitors the battery bank voltage to determine how much energy needs to be supplied to fully charge the battery bank. Basically we will talk about charging "stages". Note that solar charging terms are different vs (for example) terms used by industry for large "fork lift" battery banks):
    • Bulk: All of the energy available from solar array is sent to battery bank (battery bank from ~41 to 58 VDC)
    • Absorb: Once the battery hits ~58 VDC (charging set point), the charge controller will "turn off/off" rapidly for PWM controller (or reduce output current for MPPT charge controllers) to keep the battery bank at ~58 volts. This voltage will be held for ~2-6 hours (deeper discharged battery bank, longer "absorb" timer setting).
    • Float: Once the charge controller has determined the battery bank is "full", the charge controller will drop the set point voltage to ~55 volts and hold that until the sun sets (and/or the loads exceed the available solar charging current).
    • Discharging: Solar power no longer sufficient to hold the battery bank voltage at Absorb/Float, and when the battery bank voltage falls below ~51.2 volts, the battery is being discharged.
    You can also add other charging sources too... For large systems, you may need several solar arrays+charge controllers connected to one battery bank.

    And, if you need solar power during bad weather, you may add a DC Generator or AC Generator + AC to DC battery charger (and many larger inverters can connect directly to a 230 VAC 50 Hz generator and both recharge the battery bank and power the 230 VAC loads at the same time).

    Many of the new AC inverter+charger systems (and digitally interconnected charge controllers) are getting very complex. Before we go into any details--I would suggest understanding your loads and power needs first. We then do several "paper designs" and look at the size of battery bank and equipment you need--Then you can do a quick price check to see if the system is cost effective/capable for your needs.

    After you have done the high level paper design, you can limit your research to charge controllers, AC inverters, Batteries that will work for your system.
    second for this system, is it a good idea to charge and disharge the battery every day since the lamps will take the power from the inverter that is vonnected to the battery?
    sorry for all this questions

    Read more about lead acid batteries (there are other chemistries like, Sealed Lead Acid, LiFePO4--Various Lithium Ion chemistry type batteries, and others like NiCad, NiMH, etc.). Each has its own operational requirements.

    And even for lead acid batteries, there are those designed for deep cycle (usually used for off grid power systems) and those designed for "float" or standby use (UPS, Uninterruptable Power Supplies, used for emergency computer backup power) that are only cycled a few times in emergencies.

    You have to get the right battery for your needs.

    In general, for standard deep cycle flooded cell batteries--They start "aging" as soon as they are built... So no matter how you treat them, they may have a 5-15 year life (depending on cost, design of battery). And any cycling you do on them ages them further.

    Again, in general, you would want to cycle them down to ~75% state of charge (25% discharge) at least once per month. And 25% discharge per overnight (or daily use in bad weather) gives you ~2 days of storage with 50% maximum discharge (for longer battery life). A lead acid deep cycle battery that is cycled daily will normally last ~3-8 years or so. The deeper you cycle it, usually the less life it will have.

    Also, temperature is very important too. Batteries are usually specified to operate at 25C nominal temperature. For every 10C over 25C, a battery will be expected to last 1/2 as long. Operate at 35C, the battery will last 1/4 as long.

    Conversely, operating at 10C less than 25C, the battery will last ~2x as long. So keeping batteries from getting too hot is important (heating from charging, hot weather, etc.).

    I will stop here--I hope I am being helpful here.

    Energy usage is a highly personal set of choices--We want to help you understand the tradeoffs you will need to make for your power system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    The charge controller does just that: regulates the charging of the batteries from the solar panels. It will not allow the batteries to be overcharged, providing the settings match the batteries' requirements.

    It does not have the ability to limit discharge of the batteries through the inverter (or other DC loads). The inverter should have a Low Voltage Disconnect setting to prevent that from happening. On many inverters this is a fixed value, and may be too low to be of practical use.

    Nor will the charge controller prevent overcharging from any source other than the PV such as a charger built in to the inverter or other stand alone AC powered charger.

    Fuses or circuit breakers should be used on both the circuit from the charge controller to the batteries and from the batteries to the inverter to prevent excess current in the wires from starting a fire.
    thank you very much

    so, the blue solar mppt 150/70 will protect the battery from overcharging ,and the inverter from discharge,that is it.
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: charge controler mppt bluesolar 150/70?

    Which inverter brand/model do you plan to use? Not all models have a Low Voltage Disconnect ( LVD ) feature.
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    Yes, you are correct. The system you are looking at does allow you to make a stand alone off grid power system that can supply AC power (230 VAC at 50 Hz for Algiers, Algeria?).

    I am not familiar with Victron equipment/systems. Their details for connecting of their shared data bus between charge controller, AC inverter (I am in the US, and not a solar power systems installer)--But the basics are as you think.

    The solar panels connect to the solar charge controller which ensures the battery bank is not over charged. The charge controller "turns on" when the sun is shining on the solar panels and "turns off" when the battery bank is fully charged.

    There are two major types of solar charge controllers. One is a "PWM" (Pulse Width Modulation). More or less, it controls battery charging current by turning "on and off" very quickly (ON for 1/10th second, OFF for 1/10th second is 50% average charging current. ON for 1/100 second, OFF for 99/100 second, then only 1% of available charging current).

    The other major class is MPPT (Maximum Power Point Tracking). This is the type the Victron brand/model of charge controller you are looking at is. It contains a "switch mode digital power supply" inside. Basically, it can behave like a DC version of an AC Transformer. It can take "high voltage/low current" and "down convert" to "low current/high voltage" needed to charge the battery bank.

    For example, this allows you to put three large solar panels in series (say 10 amps Imp (current maximum power) and 30 volts Vmp (voltage maximum power) example with a 300 Watt solar panel) and down convert to 58 volts needed to charge the battery bank:

    3 panels in series * 30 volts Vmp = 90 Volts Vmp-array
    90 volts Vmp * 10 amps Imp = 900 Watt solar array
    900 Watt solar array / 58 volts battery charging = 15.5 Amps battery charging current

    So, 10 amps in from the solar array becomes ~15.5 Amps at the battery bank. This is not "free energy". Power=Volts*Current (P=I*V). So with an MPPT controller, you can run the solar array at a high voltage and efficiently down convert to lower voltage/higher current needed by the battery bank. This allows you to use smaller diameter wire and/or longer wire runs from the solar array to the battery bank.

    Note that Lead Acid flooded cell storage batteries are relatively good at storing electricity--They do have their requirements for charging current/voltage and time. You should read about the care of a lead acid battery bank (and you need to tell us what type of batteries you have--The major types used with solar power systems are flooded cell and AGM (Absorbed Glass Mat, Valve Regulated--"Sealed").

    You need to read about the care and use of Storage Batteries to understand how best to maintain them. With batteries in automobiles and trucks, we tend to "forget about them". For Off Grid power systems, you need to understand and monitor them pretty closely. It is easy to over discharge them, over charge them, forget to add water, etc. and ruin your very expensive battery bank in days/weeks/months, instead of getting the 5-15 years of life you want.

    Here are some links to Battery Information in English--And you can probably find similar in Arabic or other language(s) that you may be more familiar with (I only know English, poorly--So I am always impressed by people who visit this forum and hold very technical discussions not in their native language).

    http://www.windsun.com/Batteries/Battery_FAQ.htm
    http://www.batteryfaq.org/
    http://batteryuniversity.com/

    And, the other 1/2 of the system, connecting a battery bank to your AC inverter. Takes ~41-60 VDC power in and converts it to 230 VAC 50 Hz power out.

    The battery bank is for storing energy (electrical power) gathered by the solar array and supplying it to the AC inverter when the sun has set, or if you need power during the day, it will take power from the solar array and/or battery bank as needed.

    A basic solar power system is very much like your car's electrical system. The battery is the "heart" of the system. When the engine is stopped, the battery supplies energy to the lights/radio/etc.. When the engine is running, the alternator (or generator) will recharge the battery and supply other other loads.




    Yes, that is all of is correct. Now we get into details of your "paper design" (don't buy any parts, batteries, etc. yet until you have a paper design--It is very difficult to buy "random" solar power parts and put them together in a cost effective/reliable power system.

    So--First thing to do is to measure/estimate your power needs. 20 Lamps does not tell us much. We need to know their working voltage (230 VAC), their current (say 1 amp per Lamp * 20 lamps), and how many hours per day you will run those lamps (say 5 hours per night).
    • 230 VAC * 1 amp = 230 Watts of lamp
    • 20 lamps * 230 Watts = 4,600 Watts of lamps
    • 4,600 Watts of lamps * 5 hours of run time per evening = 23,000 Watt*Hours of energy per night
    The above is just an example, and for an off grid power system, that is a LOT OF POWER (Energy) used per night, and would be a very expensive system to build. A lot of solar panels, a very large battery bank, and relatively large AC inverter. It would be too expensive for almost anyone to build (other than very wealthy, for a business, etc.).

    However, with solar power, we have many new devices that we can use instead of "old technology" to allow us to save energy/electricity. And for off grid solar power, doing anything we can to save electricity is usually worth the time/money. It is almost always cheaper to conserve power than to generate power.

    For example, instead of using 230 Watt filament lamps (traditional light bulbs), you can get LED type bulbs (with reflectors, if needed) to direct light to where you need it at about 1/10th the amount of Watts (power) (LED lights are ~10x more expensive to purchase).

    Now each bulb may use 0.1 amp, and the battery bank+solar array+AC inverter can all be 1/10 the size. Which now is a very reasonable size off grid power system (in my imaginary system design).

    There are simple 'Watt*Hour' meters you can plug your appliances into and measure their power usage. Here is an example. You should be able to find WattHour meters locally (this is a United Kingdom/England version):

    http://www.amazon.co.uk/Plug-In-Power-and-Energy-Monitor/dp/B000Q7PJGW

    More or less, to give you an idea:
    • 1,000 WH per day (1 kWH) is a "small" system that can give you lights, radio, laptop computer, small water pump
    • 3,300 WH per day (3.3 kWH) is a "good size" system... Add refrigerator, larger well pump, clothes washing machine, etc. Pretty much would give a very energy efficient home a "modern" off grid electrical system experience (use propane, oil, petrol for heating/cooking)
    • 10 kWH per day (300 kWH per month) is would power a reasonably efficient home with some electricity for cooking, some more fans/small amount of air conditioning, etc.
    • 33 kWH per day (1,000 kWH per month) is the average power usage for a North American or European home (electric cooking, some electric hot water/heating, more computers, refrigerators, lights left on, etc.). Most people that have never worked at conservation could probably cut their electrical usage by 1/2 with conservation (new technology lighting, appliances, converting to propane for cooking/heating).
    • 100 kWH per day (3,000 kWH per month) for homes in very hot/very cold climates that use lots of electrical heat and air conditioning.
    More or less, only the 1-3.3 kWH per day systems are "comfortable" for most people. And small enough/"simple" enough for people to install the system their selves.

    The 10 kWH per day system is possible and possibly cost effective for a full off grid home/business, but that is about the largest system we would be able to help with here. (of course, we want you to be educated about solar power so you can understand the basic elements when you have discussions with a solar power company).

    Larger systems are usually too expensive for most people and most people would need to use a company/person with lots of experience with off grid power. The issues are too complex for a first time solar person with no electrical engineering experience.

    End of Part 1

    thank you very much for all this helpful informations ,
    there are only one point i do not understand ,suppose my system is like this :
    we have panels ;charge controller ;battery, inverter connected to battery and ac charge(for exemple air-conditioner)
    suppose the battery are charged,and the sun rises,do the air conditioner take power from panels through charge controller or from battery in the morning?
    because if it take power from battery that means that we have a loss of power because the sun is present and the charge controller will not charge the battery until it will drop to low voltage ,
    now if it take power from panels through charge regulator ,we have to take care of the current output.
    thank you very much again
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    westbranch wrote: »
    Which inverter brand/model do you plan to use? Not all models have a Low Voltage Disconnect ( LVD ) feature.

    i did not choose again ,but i will choose one with low voltage disconect
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    Begin Part 2:




    Note that we say "over charge" vs "surcharge" (surcharge is like a sales tax or extra fee for long distance shipping charges):



    Your English is very good and readable--Just wanted to correct a term.

    Solar panels are, sort of, variable output Solar Batteries (actually a variable current source based on the amount of sun hitting the panels--But save that for a different discussion).

    The solar charge controller monitors the battery bank voltage to determine how much energy needs to be supplied to fully charge the battery bank. Basically we will talk about charging "stages". Note that solar charging terms are different vs (for example) terms used by industry for large "fork lift" battery banks):
    • Bulk: All of the energy available from solar array is sent to battery bank (battery bank from ~41 to 58 VDC)
    • Absorb: Once the battery hits ~58 VDC (charging set point), the charge controller will "turn off/off" rapidly for PWM controller (or reduce output current for MPPT charge controllers) to keep the battery bank at ~58 volts. This voltage will be held for ~2-6 hours (deeper discharged battery bank, longer "absorb" timer setting).
    • Float: Once the charge controller has determined the battery bank is "full", the charge controller will drop the set point voltage to ~55 volts and hold that until the sun sets (and/or the loads exceed the available solar charging current).
    • Discharging: Solar power no longer sufficient to hold the battery bank voltage at Absorb/Float, and when the battery bank voltage falls below ~51.2 volts, the battery is being discharged.
    You can also add other charging sources too... For large systems, you may need several solar arrays+charge controllers connected to one battery bank.

    And, if you need solar power during bad weather, you may add a DC Generator or AC Generator + AC to DC battery charger (and many larger inverters can connect directly to a 230 VAC 50 Hz generator and both recharge the battery bank and power the 230 VAC loads at the same time).

    Many of the new AC inverter+charger systems (and digitally interconnected charge controllers) are getting very complex. Before we go into any details--I would suggest understanding your loads and power needs first. We then do several "paper designs" and look at the size of battery bank and equipment you need--Then you can do a quick price check to see if the system is cost effective/capable for your needs.

    After you have done the high level paper design, you can limit your research to charge controllers, AC inverters, Batteries that will work for your system.



    Read more about lead acid batteries (there are other chemistries like, Sealed Lead Acid, LiFePO4--Various Lithium Ion chemistry type batteries, and others like NiCad, NiMH, etc.). Each has its own operational requirements.

    And even for lead acid batteries, there are those designed for deep cycle (usually used for off grid power systems) and those designed for "float" or standby use (UPS, Uninterruptable Power Supplies, used for emergency computer backup power) that are only cycled a few times in emergencies.

    You have to get the right battery for your needs.

    In general, for standard deep cycle flooded cell batteries--They start "aging" as soon as they are built... So no matter how you treat them, they may have a 5-15 year life (depending on cost, design of battery). And any cycling you do on them ages them further.

    Again, in general, you would want to cycle them down to ~75% state of charge (25% discharge) at least once per month. And 25% discharge per overnight (or daily use in bad weather) gives you ~2 days of storage with 50% maximum discharge (for longer battery life). A lead acid deep cycle battery that is cycled daily will normally last ~3-8 years or so. The deeper you cycle it, usually the less life it will have.

    Also, temperature is very important too. Batteries are usually specified to operate at 25C nominal temperature. For every 10C over 25C, a battery will be expected to last 1/2 as long. Operate at 35C, the battery will last 1/4 as long.

    Conversely, operating at 10C less than 25C, the battery will last ~2x as long. So keeping batteries from getting too hot is important (heating from charging, hot weather, etc.).

    I will stop here--I hope I am being helpful here.

    Energy usage is a highly personal set of choices--We want to help you understand the tradeoffs you will need to make for your power system.

    -Bill

    thank you again,you should write a book about off grid system it will be very helpful
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?
    javadz wrote: »
    thank you very much for all this helpful information, there are only one point i do not understand ,suppose my system is like this :
    we have panels ;charge controller ;battery, inverter connected to battery and ac charge(for example air-conditioner) suppose the battery are charged,and the sun rises,do the air conditioner take power from panels through charge controller or from battery in the morning?

    The battery bank is what, more or less "regulates" the battery bus voltage. Somewhere between 41 volts (dead) and 59 volts (charging hard).

    In between that range, the battery will source (discharge) or sink (charge) current based on its state of charge and the total current flow in the system.
    • If you have a 20 amp load and no sun. The 20 amps will come from the battery bank to run the AC inverter.
    • If you have 10 amp current from the solar array, then you will get a 10 amp draw from the battery (10+10=20 amp load).
    • If you have 20 amp current from the solar array, then your battery will be at zero current (20+0=20 amp load).
    • If you have 50 amps from the array, then 30 amps will go to the battery and 20 amps to loa
    • If you have 50 amps from array, and no loads--Then all 50 amps will go to the battery bank.
    In general, you want ~5% to 13% charging current going to the battery bank to fully/quickly recharge the battery bank. If you have a 200 AH battery bank, then you would want:
    • 200 AH capacity * 5% = 10 amps minimum
    • 200 AH * 10% = 20 amps nominal
    • 200 AH * 13% = 26 amps "cost effective maximum
    Or, if 10% rate of charge:
    • 20 amps * 58 volts charging * 1/0.77 panel+controller derating = 1,507 Watt array (daytime charging and night-time loads)
    Note that 5% is the minimum rate of charge we would recommend (weekend/seasonal power usage). 10%-13% would be recommended for full time off grid use (9+ months a year).

    The above works well if you are charging during the day and running loads at night. However, if you also run loads during the day, you will want to have those "powered" by the solar array+the current needed to run the load.

    For an AC system that draws 10 amps:
    • 10 amps AC load + 20 amps nominal battery charging current (10% rate) = 30 Amp solar array
    Or, a solar array sized:
    • 30 amps * 58 volts charging * 1/0.77 panel+controller derating = 2,260 Watt array (daytime AC load + charging)

    We are in the land of "made up numbers" -- It will make more sense when we design the system to meet your needs.
    because if it take power from battery that means that we have a loss of power because the sun is present and the charge controller will not charge the battery until it will drop to low voltage, now if it take power from panels through charge regulator, we have to take care of the current output.

    Yes... Nothing is for free. It is very much like having a water pump, a water storage bank on a hill, and an irrigation/home water system.

    The goal is to keep the water level in the tank between 50% and 95%+ full. You are managing the water going out (house/irrigation use) against the water going in (solar panel and amount of available sun, backup generator).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    The battery bank is what, more or less "regulates" the battery bus voltage. Somewhere between 41 volts (dead) and 59 volts (charging hard).

    In between that range, the battery will source (discharge) or sink (charge) current based on its state of charge and the total current flow in the system.
    • If you have a 20 amp load and no sun. The 20 amps will come from the battery bank to run the AC inverter.
    • If you have 10 amp current from the solar array, then you will get a 10 amp draw from the battery (10+10=20 amp load).
    • If you have 20 amp current from the solar array, then your battery will be at zero current (20+0=20 amp load).
    • If you have 50 amps from the array, then 30 amps will go to the battery and 20 amps to loa
    • If you have 50 amps from array, and no loads--Then all 50 amps will go to the battery bank.
    In general, you want ~5% to 13% charging current going to the battery bank to fully/quickly recharge the battery bank. If you have a 200 AH battery bank, then you would want:
    • 200 AH capacity * 5% = 10 amps minimum
    • 200 AH * 10% = 20 amps nominal
    • 200 AH * 13% = 26 amps "cost effective maximum
    Or, if 10% rate of charge:
    • 20 amps * 58 volts charging * 1/0.77 panel+controller derating = 1,507 Watt array (daytime charging and night-time loads)
    Note that 5% is the minimum rate of charge we would recommend (weekend/seasonal power usage). 10%-13% would be recommended for full time off grid use (9+ months a year).

    The above works well if you are charging during the day and running loads at night. However, if you also run loads during the day, you will want to have those "powered" by the solar array+the current needed to run the load.

    For an AC system that draws 10 amps:
    • 10 amps AC load + 20 amps nominal battery charging current (10% rate) = 30 Amp solar array
    Or, a solar array sized:
    • 30 amps * 58 volts charging * 1/0.77 panel+controller derating = 2,260 Watt array (daytime AC load + charging)

    We are in the land of "made up numbers" -- It will make more sense when we design the system to meet your needs.



    Yes... Nothing is for free. It is very much like having a water pump, a water storage bank on a hill, and an irrigation/home water system.

    The goal is to keep the water level in the tank between 50% and 95%+ full. You are managing the water going out (house/irrigation use) against the water going in (solar panel and amount of available sun, backup generator).

    -Bill

    thank you again for all this information and to be patient to all this questions
    so ,for system with a daytime ac load(mean that we power load in the day not the night) , we have in the end of the day power input equal to power outpout and the battery will be charged.

    the only problem is when the charge controler will begin to recharge the battery :

    there is an exemple : i have a system that have an ac load of 100w and run 5hours a day that means 500wh/day
    so do we size the battery to give us 500wh/day or the panels? i will say battery because panel do not have constant power outpout ,it can give us 80w at 10h and 120w at 12h and the load must be powred by 100w for 5hours(the panel can provide us 500wh/day but in the end of the day the sum of all energy during the day)
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: charge controler mppt bluesolar 150/70?

    Size the battery bank to give you the required Watt hours per day.
    Size the solar panels and charge controller to recharge those batteries.

    500 Watt hours AC is about 588 Watt hours DC (conversion efficiency) plus the amount the inverter will draw in that time (varies with inverter). This could be another 100 Watt hours. Round up for best results.

    So you are trying to supply 700 Watt hours DC. Divide by 12 Volts nominal and you get 58 Amp hours used. You want to limit the discharge, preferably to 25% average but no more than 50%. So your battery bank becomes (58 * 4) 232 Amp hours @ 12 Volts.

    Recharging: using the 10% rule-of-thumb you want to supply 23 Amps @ 12 Volts. This will require around 400 Watts of PV on a PWM type controller or about 358 Watts using an MPPT type controller.

    Keep in mind this is just a basic explanation, not an absolute. Their are circumstances that can adjust the size of the battery bank and/or PV array up or down.
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?

    You really really need to define your power needs... If you can not run your power when the weather is bad (say an A/C system that only needs to run on sunny/hot days), then the battery bank can be relatively small.

    However, if you need to run equipment sun or rain (run your business, kids need to use the computer for homework, lights at night, etc.), then the battery bank will need to power your system even if the sun is not running--So the bank would, for example, power your loads for 2 days and 50% maximum battery discharge--Or roughly 4x your daily power needs.

    Also, you need to size the solar array based on the amount of sun light you get... For example, using the solar electricity handbook for Algiers (fixed array titled to average best angle entire year harvest):

    http://solarelectricityhandbook.com/solar-irradiance.
    Algiers
    Average Solar Insolation figures


    Measured in kWh/m2/day onto a solar panel set at a 53° angle (from vertical):
    (For best year-round performance)

    Jan
    Feb
    Mar
    Apr
    May
    Jun


    4.24

    4.88
    5.83
    6.30
    6.25
    6.59


    Jul
    Aug
    Sep
    Oct
    Nov
    Dec


    6.72

    6.67
    6.13
    5.34
    4.10
    3.84


    So, if your power needs are for AC during the summer, and lights during the winter (as an example). If you wanted 3.3 kWHs of AC power (24 hours per day, even through bad weather/no sun):

    Battery bank sizing:
    • 3,300 Watt*Hours * 1/48 volt battery bank * 1/0.85 AC inverter eff * 2 days of storage * 1/0.50 max discharge = 324 AH @ 48 volt battery bank
    To charge the battery bank, we want 5% to 13% typical rate of charge:
    • 324 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 1,220 Watt array minimum
    • 324 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 2,441 Watt array nominal
    • 324 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 3,173 Watt array "cost effective" maximum
    And then we also need to look at when you need the power... If this was relatively constant power usage throughout the year--Then I would suggest sizing the system to run ~9 months of the year from solar, and for bad weather in winter, you use a genset (and/or reduce power use), and February works out as the poorest 9 months at 4.88 hours of (average) noon time equivalent sun per day:
    • 3,300 WH * 1/0.52 overall system efficiency * 1/4.88 hours of sun = 1,300 Watt array minimum (February "break even" month)
    So, for a "generic" system (use much of the power in the evening, and provide 2 days of "no sun" power), your array would be a minimum of 1,300 Watts. And for a full time off grid home, you could use a 2,441 to 3,173 Watt array system.

    If you choose, a 10% array, then it would produce on an average February day:
    • 2,441 Watt array * 0.52 system efficiency * 4.88 hours of sun = 6,194 WH of available power in February
    So--Such a system could supply around 3.3 kWH per day (good weather or bad), and for ~9 months of the year, it will produce an (average) minimum power (during sunny weather) of ~6.2 kWH per day.

    For the average day, you could use ~3.3 kWH overnight, and an additional (6.2-3.3=) 2.9 kWH or more for daytime loads (Air Conditioning, Fans, Water Pumping, etc.).

    Does this all make sense? It really is easier to understand if we design a system to meet your needs first, then talk about other general issues once you see how the basics apply to your needs.

    Once we "define" the paper system, then you can look at the hardware to implement your specific needs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    Size the battery bank to give you the required Watt hours per day.
    Size the solar panels and charge controller to recharge those batteries.

    500 Watt hours AC is about 588 Watt hours DC (conversion efficiency) plus the amount the inverter will draw in that time (varies with inverter). This could be another 100 Watt hours. Round up for best results.

    So you are trying to supply 700 Watt hours DC. Divide by 12 Volts nominal and you get 58 Amp hours used. You want to limit the discharge, preferably to 25% average but no more than 50%. So your battery bank becomes (58 * 4) 232 Amp hours @ 12 Volts.

    Recharging: using the 10% rule-of-thumb you want to supply 23 Amps @ 12 Volts. This will require around 400 Watts of PV on a PWM type controller or about 358 Watts using an MPPT type controller.

    Keep in mind this is just a basic explanation, not an absolute. Their are circumstances that can adjust the size of the battery bank and/or PV array up or down.

    Ok thank you very much ,it begin to make sense to me.
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    You really really need to define your power needs... If you can not run your power when the weather is bad (say an A/C system that only needs to run on sunny/hot days), then the battery bank can be relatively small.

    However, if you need to run equipment sun or rain (run your business, kids need to use the computer for homework, lights at night, etc.), then the battery bank will need to power your system even if the sun is not running--So the bank would, for example, power your loads for 2 days and 50% maximum battery discharge--Or roughly 4x your daily power needs.

    Also, you need to size the solar array based on the amount of sun light you get... For example, using the solar electricity handbook for Algiers (fixed array titled to average best angle entire year harvest):

    http://solarelectricityhandbook.com/solar-irradiance.
    Algiers
    Average Solar Insolation figures


    Measured in kWh/m2/day onto a solar panel set at a 53° angle (from vertical):
    (For best year-round performance)

    Jan
    Feb
    Mar
    Apr
    May
    Jun


    4.24

    4.88
    5.83
    6.30
    6.25
    6.59


    Jul
    Aug
    Sep
    Oct
    Nov
    Dec


    6.72

    6.67
    6.13
    5.34
    4.10
    3.84


    So, if your power needs are for AC during the summer, and lights during the winter (as an example). If you wanted 3.3 kWHs of AC power (24 hours per day, even through bad weather/no sun):

    Battery bank sizing:
    • 3,300 Watt*Hours * 1/48 volt battery bank * 1/0.85 AC inverter eff * 2 days of storage * 1/0.50 max discharge = 324 AH @ 48 volt battery bank
    To charge the battery bank, we want 5% to 13% typical rate of charge:
    • 324 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 1,220 Watt array minimum
    • 324 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 2,441 Watt array nominal
    • 324 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 3,173 Watt array "cost effective" maximum
    And then we also need to look at when you need the power... If this was relatively constant power usage throughout the year--Then I would suggest sizing the system to run ~9 months of the year from solar, and for bad weather in winter, you use a genset (and/or reduce power use), and February works out as the poorest 9 months at 4.88 hours of (average) noon time equivalent sun per day:
    • 3,300 WH * 1/0.52 overall system efficiency * 1/4.88 hours of sun = 1,300 Watt array minimum (February "break even" month)
    So, for a "generic" system (use much of the power in the evening, and provide 2 days of "no sun" power), your array would be a minimum of 1,300 Watts. And for a full time off grid home, you could use a 2,441 to 3,173 Watt array system.

    If you choose, a 10% array, then it would produce on an average February day:
    • 2,441 Watt array * 0.52 system efficiency * 4.88 hours of sun = 6,194 WH of available power in February
    So--Such a system could supply around 3.3 kWH per day (good weather or bad), and for ~9 months of the year, it will produce an (average) minimum power (during sunny weather) of ~6.2 kWH per day.

    For the average day, you could use ~3.3 kWH overnight, and an additional (6.2-3.3=) 2.9 kWH or more for daytime loads (Air Conditioning, Fans, Water Pumping, etc.).

    Does this all make sense? It really is easier to understand if we design a system to meet your needs first, then talk about other general issues once you see how the basics apply to your needs.

    Once we "define" the paper system, then you can look at the hardware to implement your specific needs.

    -Bill

    Thank you very much ,this informations are very helpful ,thank you again
    ok , i will define the needs :
    first scenario :
    i have the needs load and i design the system
    an ac load that need 1000w for 5hours per day (not in night) that means(5kwh/day) all the year
    i use panels,charge controler ,battery,and inverter
    i use a 24v battery
    i choose a fixed array titled to fixed angle

    i want 50% discharge of batery and 2day autonomy

    second scenario :
    i have 1000w of panels power and i will define my needs relatively to the 1000w of panels(my panels are fixe)
    i want a load that run the day only not in night(5hour per day)
    i want 50% discharge of batery and 2day autonomy

    there is the two scenarios that will help me to understand off grid system.(definitly)
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: charge controler mppt bluesolar 150/70?

    There's something you must understand about Depth Of Discharge (DOD) and days of autonomy: they are integral.

    If your average daily DOD is 25% and your maximum DOD is 50% there's your two days of autonomy: 25% the first day, 25% the second day. On the third day you start the generator.

    5kW hours AC for one day is a lot of power. You would be better off with a 48 Volt system at that level. Roughly speaking it would require two parallel strings of 220 Amp hour batteries (sixteen in total) to supply this: 440 Amp hours @ 48 Volts. Since the load is during the day only you could get away with less battery if you can rely on the sun to power the loads 'directly' through the PV. Exact time of use is important here as the 5 hours running time will be about all the sun you get. If this is the wrong time of day (centered on noon production), you're stuck with the big battery bank.

    In which case you'd be looking at about 2750 Watts of PV to recharge with.
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?
    javadz wrote: »
    first scenario :
    i have the needs load and i design the system
    an ac load that need 1000w for 5hours per day (not in night) that means(5kwh/day) all the year
    i use panels,charge controller, battery, and inverter
    i use a 24v battery
    i choose a fixed array titled to fixed angle
    i want 50% discharge of battery and 2day autonomy

    OK--Assuming you are in Algiers (or in the area), it would look like:

    5,000 WH per day * 1/0.85 inverter eff * 1/24 volt battery bank * 2 days * 1/0.50 max discharge = 980 AH @ 24 volts

    As Marc says, a 10% rate of charge would be ~98 amps. That would require two larger MPPT charge controllers ($600 USD or so). If you go to 48 volts, then the current in the system (charging/discharging would be 1/2 as much.

    Also, I do not like lots of batteries in parallel (i.e., 4x 220 AH batteries)... I would suggest a single string of batteries as ideal, with 2-3 parallel strings as OK. There are a lot of discussions about batteries still to be held... Don't forget to ask when we get to that point.

    Sizing the solar array, looking at the table of hours of sun per day--Remember these are something like 20 year averages. You can have +/- 10% or more changes due to weather year to year, and possible weeks or more of unusual cloudy/stormy weather--So a backup genset is usually required anyway. Using 3.84 hours of sun:
    • 5,000 WH per day * 1/0.52 system efficiency * 1/3.84 hours of sun December = 2,504 Watt array minimum
    You should never plan on using 100% of predicted power from a solar power system... Usually closer to 66 to 75% of predicted power--If you really want to avoid a genset, then you could oversize the array to:
    • 2,504 Watt array * 1/0.66 derating (age/weather/real battery performance) = 3,794 Watt array ("cost effective" oversizing)
    • 3,794 Watt array * 0.77 panel+charge controller deratings * 1/29 volts charging = 101 Amps "typical" max charging current
    • 101 Amps charging / 980 AH battery bank = 0.103 = 10.3% nominal charging current
    So--That would be a "well balanced" designed. But, as Marc says, I too would suggest a 48 volt battery bank (and find a "smaller" 48 volt AC inverter if you can--sometimes difficult).

    The generator could be a 10% rate of charge (smaller genset):
    • 98 amps charging current * 29 volts charging * 1/0.8 charger eff * 1/0.67 charger power factor * 1/0.80 genset derating = 6,628 kWatt "nominal" generator rating
    This number can be "played with"---If you get a more efficient battery charger, then it may look something like:
    • 98 amps charging * 29 volts * 1/0.9 charger eff * 1/0.95 power factor * 1/0.8 genset derating = 4,133 Watt nominal genset
    second scenario :
    i have 1000w of panels power and i will define my needs relatively to the 1000w of panels(my panels are fixed)
    i want a load that run the day only not in night(5hour per day)
    i want 50% discharge of battery and 2 day autonomy
    1,000 watts of panels would support a battery bank of:
    • 1,000 watt panels * 0.77 panel+controller derating * 1/24 volt battery * 1/0.13 rate of charge = 245 AH @ 24 volt minimum battery bank
    • 1,000 watt panels * 0.77 panel+controller derating * 1/24 volt battery * 1/0.10 rate of charge = 321 AH @ 24 volt nominal battery bank
    • 1,000 watt panels * 0.77 panel+controller derating * 1/24 volt battery * 1/0.05 rate of charge = 642 AH @ 24 volt maximum battery bank
    Picking 10% rate of charge, the average power for 9 months a year minimum sun in Algiers is:
    • 1,000 Watt solar array * 0.52 system efficiency * 3.88 hours of sun = 2,018 WH per day
    Assuming 2 days of autonomy and 50% maximum discharge on a 10% battery bank:
    • 321 AH * 24 volts * 1/2 days autonomy * 0.50 max discharge * 0.85 Inverter Efficiency = 1,637 Watt*Hours per day from battery bank
    That is how I would work the question... You can have a larger or smaller battery bank. I tend towards smaller battery banks (less money in batteries, if you kill a battery bank from over discharging, you will spend less money replacing it. Also, for daily usage, having a larger solar array to battery bank ratio means less issues with monitoring battery bank state of charge).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    There's something you must understand about Depth Of Discharge (DOD) and days of autonomy: they are integral.

    If your average daily DOD is 25% and your maximum DOD is 50% there's your two days of autonomy: 25% the first day, 25% the second day. On the third day you start the generator.

    5kW hours AC for one day is a lot of power. You would be better off with a 48 Volt system at that level. Roughly speaking it would require two parallel strings of 220 Amp hour batteries (sixteen in total) to supply this: 440 Amp hours @ 48 Volts. Since the load is during the day only you could get away with less battery if you can rely on the sun to power the loads 'directly' through the PV. Exact time of use is important here as the 5 hours running time will be about all the sun you get. If this is the wrong time of day (centered on noon production), you're stuck with the big battery bank.

    In which case you'd be looking at about 2750 Watts of PV to recharge with.

    thank you again for your response
    "Since the load is during the day only you could get away with less battery if you can rely on the sun to power the loads 'directly' through the PV"
    how i can do this since the load are connected to battery and ,the power from the pv is not constant ,because my load need 1000w each hour and the pv cannot give me this power each hour it can give me 400w at 10h and 1200w at 12h it's not a constant source of power?
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?

    It all depends on your loads... If you can turn your 1,000 watt load off when the sun is not shining--Then you do not need to store much power.

    If you need 1,000 watts * 5 hours every day, rain or sun, then you need to have the battery bank sized to produce the power during bad weather (during dark cloudy conditions, it is not uncommon to have 5% or less power generation by solar array--virtually zero useful power during bad weather).

    And, the array needs to recharge the battery bank plus support the loads once the sun returns.

    In general, it is difficult to justify storing more than ~2 days of energy (a very large lead acid battery bank is expensive and has its own issues). Usually, your best bet is to plan on using a generator if you have >2 days of bad weather in a row (and/or reduce or turn off loads until sun returns).

    Power usage is a highly personal set of choices. You have to make the cost/benefit decisions on what will work best for you (and what you can afford).

    We try to help you understand the basis for those decisions and what configurations/designs will work best for you.

    You have not discussed any details about your loads--Can you give us some information? Sometimes, there are better solutions out there that can reduce your needs for off grid solar power. Pumping water, as an example, there are lots of options that can work out much cheaper than a full off grid AC + battery bank power system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    OK--Assuming you are in Algiers (or in the area), it would look like:

    5,000 WH per day * 1/0.85 inverter eff * 1/24 volt battery bank * 2 days * 1/0.50 max discharge = 980 AH @ 24 volts

    As Marc says, a 10% rate of charge would be ~98 amps. That would require two larger MPPT charge controllers ($600 USD or so). If you go to 48 volts, then the current in the system (charging/discharging would be 1/2 as much.

    Also, I do not like lots of batteries in parallel (i.e., 4x 220 AH batteries)... I would suggest a single string of batteries as ideal, with 2-3 parallel strings as OK. There are a lot of discussions about batteries still to be held... Don't forget to ask when we get to that point.

    Sizing the solar array, looking at the table of hours of sun per day--Remember these are something like 20 year averages. You can have +/- 10% or more changes due to weather year to year, and possible weeks or more of unusual cloudy/stormy weather--So a backup genset is usually required anyway. Using 3.84 hours of sun:
    • 5,000 WH per day * 1/0.52 system efficiency * 1/3.84 hours of sun December = 2,504 Watt array minimum
    You should never plan on using 100% of predicted power from a solar power system... Usually closer to 66 to 75% of predicted power--If you really want to avoid a genset, then you could oversize the array to:
    • 2,504 Watt array * 1/0.66 derating (age/weather/real battery performance) = 3,794 Watt array ("cost effective" oversizing)
    • 3,794 Watt array * 0.77 panel+charge controller deratings * 1/29 volts charging = 101 Amps "typical" max charging current
    • 101 Amps charging / 980 AH battery bank = 0.103 = 10.3% nominal charging current
    So--That would be a "well balanced" designed. But, as Marc says, I too would suggest a 48 volt battery bank (and find a "smaller" 48 volt AC inverter if you can--sometimes difficult).

    The generator could be a 10% rate of charge (smaller genset):
    • 98 amps charging current * 29 volts charging * 1/0.8 charger eff * 1/0.67 charger power factor * 1/0.80 genset derating = 6,628 kWatt "nominal" generator rating
    This number can be "played with"---If you get a more efficient battery charger, then it may look something like:
    • 98 amps charging * 29 volts * 1/0.9 charger eff * 1/0.95 power factor * 1/0.8 genset derating = 4,133 Watt nominal genset


    1,000 watts of panels would support a battery bank of:
    • 1,000 watt panels * 0.77 panel+controller derating * 1/24 volt battery * 1/0.13 rate of charge = 245 AH @ 24 volt minimum battery bank
    • 1,000 watt panels * 0.77 panel+controller derating * 1/24 volt battery * 1/0.10 rate of charge = 321 AH @ 24 volt nominal battery bank
    • 1,000 watt panels * 0.77 panel+controller derating * 1/24 volt battery * 1/0.05 rate of charge = 642 AH @ 24 volt maximum battery bank
    Picking 10% rate of charge, the average power for 9 months a year minimum sun in Algiers is:
    • 1,000 Watt solar array * 0.52 system efficiency * 3.88 hours of sun = 2,018 WH per day
    Assuming 2 days of autonomy and 50% maximum discharge on a 10% battery bank:
    • 321 AH * 24 volts * 1/2 days autonomy * 0.50 max discharge * 0.85 Inverter Efficiency = 1,637 Watt*Hours per day from battery bank
    That is how I would work the question... You can have a larger or smaller battery bank. I tend towards smaller battery banks (less money in batteries, if you kill a battery bank from over discharging, you will spend less money replacing it. Also, for daily usage, having a larger solar array to battery bank ratio means less issues with monitoring battery bank state of charge).

    -Bill

    thank you again for your precious informations
    for the second scenario :
    1,000 Watt solar array * 0.52 system efficiency * 3.88 hours of sun = 2,018 WH per day
    ok i understand this
    but for me since i can have 2018wh/day from panels :
    my battery will be :
    2108/24=87.33AH
    and for 50% discharge it will be :87.33AH/0.5=174AH,
    and for two days autonomy it will be :174AH*2=348AH
    that means that i must buy 348AH of battery at 24v
    and my charge will be :
    since i have 87.33AH of energy per day from pv ;than 87.33*24=2108wh /5h=421w that mean i can power a load for 5hours with 421w (that mean i will take 17Ah (421/24) from battery each hour for 5ours per day with 24v)
    now we suppose i designed my system with 348ah of battery ,and i suppose the battery are fully charged,i put a load that demand 421w ,the sun is shining:
    1-supose the current coming from panel is 17Ah(that what need my load) ,
    did this current will go :
    1- to the inverter directly through battery(since the inverter is in paralele with battery) this case i dont understand how it will be ,because since the charge regulator are in paralele with battery and the inverter are in paralel with battery ,so when battery are fully charged ,the charge controler will not provide current to battery ,

    2-or the battery will provide the 17Ah ,to the inverter,all day (5hours per day=87.33Ah) ,but in the end of day the battery charge will be at 50% and one day autonomy) and i do not know when the charge controler will begin to recharge the battery,at what state of charge (75%,50%,25%) or it will recharge the battery as soon as it's not fully charged)
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    It all depends on your loads... If you can turn your 1,000 watt load off when the sun is not shining--Then you do not need to store much power.

    If you need 1,000 watts * 5 hours every day, rain or sun, then you need to have the battery bank sized to produce the power during bad weather (during dark cloudy conditions, it is not uncommon to have 5% or less power generation by solar array--virtually zero useful power during bad weather).

    And, the array needs to recharge the battery bank plus support the loads once the sun returns.

    In general, it is difficult to justify storing more than ~2 days of energy (a very large lead acid battery bank is expensive and has its own issues). Usually, your best bet is to plan on using a generator if you have >2 days of bad weather in a row (and/or reduce or turn off loads until sun returns).

    Power usage is a highly personal set of choices. You have to make the cost/benefit decisions on what will work best for you (and what you can afford).

    We try to help you understand the basis for those decisions and what configurations/designs will work best for you.

    You have not discussed any details about your loads--Can you give us some information? Sometimes, there are better solutions out there that can reduce your needs for off grid solar power. Pumping water, as an example, there are lots of options that can work out much cheaper than a full off grid AC + battery bank power system.

    -Bill
    thank you again
    i did not decide yet what will be my load,i just try to understand the off grid system,
    i try to build an off grid system that contain panels(up to 1000w),blue solar charge controler 150/70mppt ,battery ,and an inverter
    when the system will work and i see how much power i will get ,than i will choose my load.
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?
    javadz wrote: »
    thank you again for your precious informations
    for the second scenario :
    1,000 Watt solar array * 0.52 system efficiency * 3.88 hours of sun = 2,018 WH per day
    ok i understand this
    but for me since i can have 2018wh/day from panels :
    my battery will be :
    2108/24=87.33AH
    and for 50% discharge it will be :87.33AH/0.5=174AH,
    and for two days autonomy it will be :174AH*2=348AH
    that means that i must buy 348AH of battery at 24v
    and my charge will be :
    since i have 87.33AH of energy per day from pv ;than 87.33*24=2108wh /5h=421w that mean i can power a load for 5hours with 421w (that mean i will take 17Ah (421/24) from battery each hour for 5ours per day with 24v)

    now we suppose i designed my system with 348ah of battery ,and i suppose the battery are fully charged,i put a load that demand 421w ,the sun is shining:
    1-supose the current coming from panel is 17Ah(that what need my load) ,
    did this current will go :
    1- to the inverter directly through battery(since the inverter is in parallel with battery) this case i don't understand how it will be, because since the charge regulator are in parallel with battery and the inverter are in parallel with battery, so when battery are fully charged, the charge controller will not provide current to battery.

    2-or the battery will provide the 17Ah ,to the inverter,all day (5hours per day=87.33Ah) ,but in the end of day the battery charge will be at 50% and one day autonomy) and i do not know when the charge controller will begin to recharge the battery, at what state of charge (75%,50%,25%) or it will recharge the battery as soon as it's not fully charged)

    In general, if the sun is not up, the battery will supply all current (energy) needed to run the AC inverter and any DC loads. The battery will hold ~24 volts and the current will be what the loads demand.

    If they sun is shining, the charge controller will take all available current from the solar array (more current as the sun rises towards noon)--And the when the battery bus voltage hits ~27.6 volts (float charging) or ~29 volts (absorb charging)--The solar charge controller will reduce its average charging current if the battery voltage exceeds the set-point, or it will attempt to output more current when the battery voltage falls below the set-point.

    Don't get too concerned about the details--It does work pretty well...

    Where you can get into issues is if you use a lot of current during the day (say irrigation)--Then the high average load does subtract available charging current from the battery bank. So--You may need to add more solar panels for the situation where you have have higher average daily loads plus night time loads.

    Given that, on average, solar panels are at a historic low price--Adding solar panels to an off grid power system is not nearly as painful as it used to be even 5-10 years ago.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    In general, if the sun is not up, the battery will supply all current (energy) needed to run the AC inverter and any DC loads. The battery will hold ~24 volts and the current will be what the loads demand.

    If they sun is shining, the charge controller will take all available current from the solar array (more current as the sun rises towards noon)--And the when the battery bus voltage hits ~27.6 volts (float charging) or ~29 volts (absorb charging)--The solar charge controller will reduce its average charging current if the battery voltage exceeds the set-point, or it will attempt to output more current when the battery voltage falls below the set-point.

    Don't get too concerned about the details--It does work pretty well...

    Where you can get into issues is if you use a lot of current during the day (say irrigation)--Then the high average load does subtract available charging current from the battery bank. So--You may need to add more solar panels for the situation where you have have higher average daily loads plus night time loads.

    Given that, on average, solar panels are at a historic low price--Adding solar panels to an off grid power system is not nearly as painful as it used to be even 5-10 years ago.

    -Bill
    thank you again ,
    ok it begin to be simple to me
    well,ok the only thing that upset me is the dichareg and charge of the battery every day ,it seems like i will reduce their life.
    second thing is i try to now what is the set point voltage of battery that the charge controler will begin to recharge the battery(because if it wait until the battery down to like 50% to begin to recharge the batterty ,then there will be not sun to power the battery(after 5hours in the day)

    third like i say ,i have 1000w of panels and a blue solar charge controler mppt 150/70 ,now i will try to buy battery and an inverter
    what whould you suggest to me to have a 24volt system with ac load.?

    you did not tell me if this reasoning is correct(without loss in the system) :
    1000 Watt solar array * 0.52 system efficiency * 3.88 hours of sun = 2,018 WH per day
    ok i understand this
    but for me since i can have 2018wh/day from panels :
    my battery will be :
    2108/24=87.33AH
    and for 50% discharge it will be :87.33AH/0.5=174AH,
    and for two days autonomy it will be :174AH*2=348AH
    that means that i must buy 348AH of battery at 24v
    and my charge will be :
    since i have 87.33AH of energy per day from pv ;than 87.33*24=2108wh /5h=421w that mean i can power a load for 5hours with 421w (that mean i will take 17Ah (421/24) from battery each hour for 5ours per day with 24v)

    now is that this connection correct :(charge regulator like blue solar mppt 150/70 without dc load)

    offgrid1.png
    excuse me for all this disturbing questions , i know i ask a lot.
    thank you agin for your help
  • BB.BB. Super Moderators, Administrators Posts: 32,018 admin
    Re: charge controler mppt bluesolar 150/70?
    javadz wrote: »
    well,ok the only thing that upset me is the discharge and charge of the battery every day ,it seems like i will reduce their life.

    Lead Acid Batteries "age" in two ways... One is pure age. They are chemical devices that slowly "die" over time from the day they are manufactured.

    The second is cycling (the following is a very great simplification--And, like many engineering issues, the devil is in the details). For Lead Acid deep cycle storage, there are ones designed for "standby use" (only a few deep cycles and they would be dead--Such as computer uninterruptible power supplies).

    Others, like for cars and trucks Starting, Lighting, and Ignition (SLI). These are designed for short/heavy current (cranking the engine, running accessories, glow plug heating on diesels, etc.). If you cycle these deeper than 10-15%, they will not last very long.

    And then the "true" deep cycle battery. More or less, they are designed to be discharge from 75% state of charge to less than 50% state of charge, and back up again to ~100%. And with Lead Acid Batteries, they may last 2,000 cycles with 25% (shallow discharge) and only 500 cycles with 80% discharge (very deep cycling). Interestingly--To a first approximation--If you get 2,000 cycles with 25% discharge, you will get ~1,000 cycles with 50% discharge. The battery will supply about the same amount of energy over its life--Either divided with a lot of "small cycles" or fewer deep cycles.

    We use a lot of rules of thumb to help us "size" a system to quickly and easily give us a system that will (or at least should) give the owner a reliable system that meets their needs (cost effectively).
    second thing is i try to now what is the set point voltage of battery that the charge controller will begin to recharge the battery(because if it wait until the battery down to like 50% to begin to recharge the battery ,then there will be not sun to power the battery (after 5 hours in the day).

    There are different schemes for operating an off grid power system. But, the basic one is that the Solar Charge controller will recharge the battery bank back full every day. And if the battery is discharged for 2 days, it may take several days to fully recharge the battery bank.

    If you over discharge the battery bank, and/or do other things wrong (forget to keep the electrolyte over the plates, etc.)--Lead acid batteries can be killed pretty quickly.

    That is why we tell people to get "inexpensive" batteries the first time--Most people "murder" their first battery bank or two as they learn how to run their system.

    If you are interested, perhaps you can build a "small" system. Perhaps 1,000 WH per day 12 VDC with a small 300 Watt AC inverter and experiment with it (around 500 watts of panels and a 400 AH @ 12 volt battery bank).
    third like i say ,i have 1000w of panels and a blue solar charge controller mppt 150/70, now i will try to buy battery and an inverter what would you suggest to me to have a 24volt system with ac load.?

    Victron, as I understand, makes equipment. For a 1,000 Watt array on a 24 volt system, you would only need ~30 amp charge controller--The 70 Amp Victron is on the "large" side (70 amp controller).

    Perhaps one of our European members can tell you about Victron and other vendors that may be good choices for your needs.

    For the AC inverter, with a 321 AH @ 24 volt battery bank, a ~1,500 Watt AC inverter would be a good fit (for that size battery bank). The battery bank would have difficulties supplying more Wattage (you would take more current than the battery bank could supply).
    you did not tell me if this reasoning is correct(without loss in the system) :
    1000 Watt solar array * 0.52 system efficiency * 3.88 hours of sun = 2,018 WH per day
    This is assuming a ~52% efficient system from Solar panel derating through charge controller to battery bank to AC inverter losses:
    • Total efficiency = 0.81 solar panel derating * 0.95 charge controller efficiency * 0.80 flooded cell battery eff * 0.85 inverter eff = 0.52 = 52% end to end efficiency
    ok i understand this
    but for me since i can have 2018wh/day from panels :
    my battery will be :
    2108/24=87.33AH
    and for 50% discharge it will be :87.33AH/0.5=174AH,
    and for two days autonomy it will be :174AH*2=348AH
    that means that i must buy 348AH of battery at 24v
    and my charge will be :
    since i have 87.33AH of energy per day from pv ;than 87.33*24=2108wh /5h=421w that mean i can power a load for 5hours with 421w (that mean i will take 17Ah (421/24) from battery each hour for 5ours per day with 24v)

    The calculations are "rough" numbers... For solar power, anything within +/-10% is pretty much "the same" (that is the level of "accuracy" for most solar calculations).

    We are sizing the battery bank based on expected daily power draw. The solar array is calculated two ways--The first is based on the needs of the battery bank itself (5-13% or so charging current). The second is based on the amount of sun for the location it will be installed (I usually use ~9 months worst case, or ~4.0 hours of sun for planning).

    It is sort of minimum set of calculations. For places/seasons with lots of sun, the array will produce "More Power" than the battery should store daily (over paneled). But you still need to meet the minimum charging current for the battery bank (5% minimum rate of charge for weekend/summer usage, 10%+ for daily usage for full time living).

    In general, during summer you will have "more power" than the battery can "supply" (2 days of autonomy and 50% maximum discharge).

    During winter, the array cannot supply all the power--And you either don't use power (or don't use very much power), or you use a generator to make up for poor solar power production.
    now is that this connection correct :(charge regulator like blue solar mppt 150/70 without dc load)

    offgrid1.png

    Yes, that the above is the basic idea of how the system is connected together.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • javadzjavadz Registered Users Posts: 20
    Re: charge controler mppt bluesolar 150/70?
    BB. wrote: »
    Lead Acid Batteries "age" in two ways... One is pure age. They are chemical devices that slowly "die" over time from the day they are manufactured.

    The second is cycling (the following is a very great simplification--And, like many engineering issues, the devil is in the details). For Lead Acid deep cycle storage, there are ones designed for "standby use" (only a few deep cycles and they would be dead--Such as computer uninterruptible power supplies).

    Others, like for cars and trucks Starting, Lighting, and Ignition (SLI). These are designed for short/heavy current (cranking the engine, running accessories, glow plug heating on diesels, etc.). If you cycle these deeper than 10-15%, they will not last very long.

    And then the "true" deep cycle battery. More or less, they are designed to be discharge from 75% state of charge to less than 50% state of charge, and back up again to ~100%. And with Lead Acid Batteries, they may last 2,000 cycles with 25% (shallow discharge) and only 500 cycles with 80% discharge (very deep cycling). Interestingly--To a first approximation--If you get 2,000 cycles with 25% discharge, you will get ~1,000 cycles with 50% discharge. The battery will supply about the same amount of energy over its life--Either divided with a lot of "small cycles" or fewer deep cycles.

    We use a lot of rules of thumb to help us "size" a system to quickly and easily give us a system that will (or at least should) give the owner a reliable system that meets their needs (cost effectively).



    There are different schemes for operating an off grid power system. But, the basic one is that the Solar Charge controller will recharge the battery bank back full every day. And if the battery is discharged for 2 days, it may take several days to fully recharge the battery bank.

    If you over discharge the battery bank, and/or do other things wrong (forget to keep the electrolyte over the plates, etc.)--Lead acid batteries can be killed pretty quickly.

    That is why we tell people to get "inexpensive" batteries the first time--Most people "murder" their first battery bank or two as they learn how to run their system.

    If you are interested, perhaps you can build a "small" system. Perhaps 1,000 WH per day 12 VDC with a small 300 Watt AC inverter and experiment with it (around 500 watts of panels and a 400 AH @ 12 volt battery bank).



    Victron, as I understand, makes equipment. For a 1,000 Watt array on a 24 volt system, you would only need ~30 amp charge controller--The 70 Amp Victron is on the "large" side (70 amp controller).

    Perhaps one of our European members can tell you about Victron and other vendors that may be good choices for your needs.

    For the AC inverter, with a 321 AH @ 24 volt battery bank, a ~1,500 Watt AC inverter would be a good fit (for that size battery bank). The battery bank would have difficulties supplying more Wattage (you would take more current than the battery bank could supply).


    This is assuming a ~52% efficient system from Solar panel derating through charge controller to battery bank to AC inverter losses:
    • Total efficiency = 0.81 solar panel derating * 0.95 charge controller efficiency * 0.80 flooded cell battery eff * 0.85 inverter eff = 0.52 = 52% end to end efficiency


    The calculations are "rough" numbers... For solar power, anything within +/-10% is pretty much "the same" (that is the level of "accuracy" for most solar calculations).

    We are sizing the battery bank based on expected daily power draw. The solar array is calculated two ways--The first is based on the needs of the battery bank itself (5-13% or so charging current). The second is based on the amount of sun for the location it will be installed (I usually use ~9 months worst case, or ~4.0 hours of sun for planning).

    It is sort of minimum set of calculations. For places/seasons with lots of sun, the array will produce "More Power" than the battery should store daily (over paneled). But you still need to meet the minimum charging current for the battery bank (5% minimum rate of charge for weekend/summer usage, 10%+ for daily usage for full time living).

    In general, during summer you will have "more power" than the battery can "supply" (2 days of autonomy and 50% maximum discharge).

    During winter, the array cannot supply all the power--And you either don't use power (or don't use very much power), or you use a generator to make up for poor solar power production.



    Yes, that the above is the basic idea of how the system is connected together.

    -Bill

    thank you again for your precious informations

    excuse me but i did not understan,this :"-The first is based on the needs of the battery bank itself (5-13% or so charging current)"
    and this:"(5% minimum rate of charge for weekend/summer usage, 10%+ for daily usage for full time living)."
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: charge controler mppt bluesolar 150/70?

    The charge rate is expressed as a percentage of the battery bank's Amp hours (at the 20 hour rate).
    For systems that have no loads on during charging (such as one meant to supply nighttime lighting only) you can use the manufacturer recommended minimum of 5%:

    220 Amp hour battery * 5% = 11 Amps peak charging current.

    For systems that are in daily use (that is loads drawing while charging at the same time) you target 10%:

    220 Amp hour battery * 10% = 22 Amps peak charging current.

    Other circumstances such as heavy loads or poor insolation conditions may warrant a higher charge rate. 13% has traditionally been the practical maximum because above that you spend a lot of money on PV that doesn't do much most of the time; it simply isn't needed. With PV prices as low as they are now that could be 15%, but then you get into the area of low charge acceptance for flooded batteries. AGM's can take more current.

    Keep in mind this is a peak charge current, not a constant one, and may not necessarily be seen because of the many factors involved in current demand. It is important to recognize also that the actual charge rate will be the controller output minus the load demand: if you have 22 Amps from the controller and loads take 5 Amps then the net amount going to the batteries is (22-5) 17 Amps.

    Another caveat: the 'tall case' batteries such as L16's require that 10% net rate due to the need for fairly long Absorb to mix the electrolyte and avoid stratification; the faster you can get them through Bulk the more time there is for Absorb before the sun goes down.
Sign In or Register to comment.