Help needed: who can rock the ad hoc?

HamishHamish Registered Users Posts: 5
Hello, if anyone has the inclination,
I have been collecting bits and pieces for sometime now. I have 14 shuoco 165w modules 13 100ah AGM batteries (12v) with a promise of 20 more over the next 6 months. a 5k genny and a harbor freight 12 vdc 2 k inverter. I also have an rv charger that is 35 amp 3 stage 12 vdc for battery charging from genny. I know I need a charge controller,and that my inverter is not ideal as it is 12 vdc and with 2kw of panels that is not recommended.

Problem is, I need to buy a charge controller, and I have little to no money.

I am so close to having power.... How should I set things up? Is there a decent charge controller for this hodge podge in the hundred dollar range? What sort of strings? Anybody who cares to help will be a hero.
The only power we have currently is the genny which uses the rv power converter to charge 3 [email protected] 12 vdc. We only use ac when genny is running.

Thanks to all who help


Hamish

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    Re: Help needed: who can rock the ad hoc?

    Oh boy Hamish... You have a real mix of hardware.

    And off grid solar is never really "cheap".

    What is your 12 volt inverter wattage rating?

    I can suggest a setup that can work--It will not be "efficient", but with all of the panels and batteries you have available (more than you can really use on a single 12 volt system), can get something that will work better than running a 5kWatt genset all of the time.

    By the way, have you been keeping the batteries charged? Putting each battery on a charger for ~24 hours every 1-4 months (for AGMs) or so would be a good idea. If you let them sit for 6-12+ months uncharged, there is a good chance they are not any good by now.

    How much power is (per day, peak wattage, etc.) is "useful" for your needs?

    You have two choices, design the system to your needs--Or design the system to what you can afford, and then power what it will power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 5,658 ✭✭✭✭✭
    Re: Help needed: who can rock the ad hoc?

    What is the source of the batteries? pulls from UPS systems? they may or may not be good, and you need to figure out what you have. Never good having so many multiple batteries in parallel, if you want to stay 12 volt, you don't have much option other than putting the batteries in parallel. With unknown capacities, batteries loose capacity as they age, they will discharge to the lowest capacity as the stronger batteries are drawn down trying to bring up the lower capacity batteries. In time you will want to switch to a 48 volt system, if these are in good shape, the batteries themselves have some real value, perhaps $15 each just in lead..
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • HamishHamish Registered Users Posts: 5
    Re: Help needed: who can rock the ad hoc?

    Lol, I hear what your saying. The end goal is a 24 or48 vdc system. The missing piece being an inverter. We have a tiny house so loads are currently very small. We currently use 12 vdc lighting salvaged from junked cars and campers, so that's a small load, we have be collecting led lightbulbs for when the ac is flowing. The only ac appliance we currently are using is a little coffee grinder. The goal is to be able to use them. There are a couple other tinyhousers who will be moving to the farm this winter, and would like to Have enough juice to run a washing machine a couple times a week and maybe a deep freezer. With what I currently have.

    I am hoping to pick up a better inverter/charger/controller by winters end and have a real 2k system.

    I have been picking up pieces for about a year. And have been maintaining batteries monthly. I have spent about 2k on the system so far, so I have been buying by price. I am a small scale organic egg farmer a d don't make very much. Especy in winter.

    Thanks for helping BB.

    The inverter range is 2000 watt continuous 4000 watt peak Cen-tech from harbor frieght. 60532 is their item number
  • HamishHamish Registered Users Posts: 5
    Re: Help needed: who can rock the ad hoc?

    Yes they are UPS pulls 4 years in on a ten year warranty. They all read 12.9 to 13.3 without load. At 72 lbs each probably right about the lead content
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Help needed: who can rock the ad hoc?
    Hamish wrote: »
    Hello, if anyone has the inclination,
    I have been collecting bits and pieces for sometime now. I have 14 shuoco 165w modules 13 100ah AGM batteries (12v) with a promise of 20 more over the next 6 months. a 5k genny and a harbor freight 12 vdc 2 k inverter. I also have an rv charger that is 35 amp 3 stage 12 vdc for battery charging from genny. I know I need a charge controller,and that my inverter is not ideal as it is 12 vdc and with 2kw of panels that is not recommended.

    Problem is, I need to buy a charge controller, and I have little to no money.

    I am so close to having power.... How should I set things up? Is there a decent charge controller for this hodge podge in the hundred dollar range? What sort of strings? Anybody who cares to help will be a hero.
    The only power we have currently is the genny which uses the rv power converter to charge 3 [email protected] 12 vdc. We only use ac when genny is running.

    Thanks to all who help


    Hamish

    What's wrong with this picture?

    Thirteen 12 Volt batteries. I hope you aren't trying to run them all at once in parallel because there is no possibility of the current being even with that many. Also that's 1300 Amp hours which would require ridiculous amounts of current to charge. The 35 Amp charger isn't going t touch it. Clearly you don't need that much battery so ... select the best and sell the rest. Otherwise they will just go bad and you will get no value from them at all.

    Fourteen 165 Watt panels = 2310 Watt array. Too many panels for any one controller on 12 Volts. That much PV would require an 80 Amp MPPT on 24 Volts. Such is not cheap, and you're on a budget.

    If for now you reduce the battery bank to three or four @ 100 Amp hours each you'll have a couple of kW hours to work with and you'll only need four or five of those panels to keep them up. I'm not sure what the specs are on those panels, but I suspect they are 35 Vmp? That would be normal in the 165 Watt range, and that would mean you have to have the MPPT controller to down-convert to a 12 Volt system and that means money. The other option is to double up on panels and 'waste' half the power by using a PWM to pass just the current available. This should be something like a C40 to handle both the Voltage and current potential. Still money at >$100.

    Another option would be to set up the array and batteries as 24 Volts now, and try to balance the 12 Volt loads between two halves of it as best you can. Know in advance this means the batteries will unbalance and ultimately die an early death. But if you're willing to sacrifice a few batteries for a few years it may work out better as 200 Amp hours @ 24 Volts is the same power as 400 @ 12 but can use a smaller, less expensive PWM charge controller like a SunSaver 20 @ $84.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Help needed: who can rock the ad hoc?

    As to running the washer and deep freezer ... that's a whole 'nother game.
    Freezer is likely to consume 1kW hour per day all on its own, and the washer is likely to have a nasty start-up demand (best run off the generator).

    This thread once again points out the difficulties in trying to expand a system and the self-inflicted roadblocks caused by buying piecemeal. :cry:
  • ThomThom Solar Expert Posts: 196 ✭✭✭
    Re: Help needed: who can rock the ad hoc?

    Why not think small for now ? Say 400w of panel a couple of batteries and a smaller invertor say a 750w harbor freight or invertor just big enough to run The coffee grinder.

    Thom
    Off grid since 1984. 430w of panel, 300w suresine , 4 gc batteries 12v system, Rogue mpt3024 charge controller , air breeze windmill, Mikita 2400w generator . Added [email protected] 100w panel with a midnight brat 
  • PhotowhitPhotowhit Solar Expert Posts: 5,658 ✭✭✭✭✭
    Re: Help needed: who can rock the ad hoc?

    Where are you located?

    I think small deep freezers run around 1/2 Kwh a day, likely do able on a small system, and if you load shift and run the washer during the day you could likely run it on a small system, but your at the upper end of things and will need to monitor the State of Charge (SOC) and run your generator if your getting low, likely every over cast day. The bad news is both of these use a motor and you will shorten their lives if you run them on a Modified Sine Wave (MSW) inverter, particularly a cheap one.

    What is the VMP of your panels? if they are 24v panels (as 'Coot said around 35 volts VMP) then I would look to setting up a quick and dirty 24 volt system. I can point you to some inexpensive 24v used true sine inverters, but cheap means $300, I would be sure to get a charge controller that will work with a higher voltage system, so you won't waste money and just have to replace it in a year when you upgrade to a higher voltage.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • HamishHamish Registered Users Posts: 5
    Re: Help needed: who can rock the ad hoc?

    Hey if it can't be done, it can't. I am not in some stage of desperation. The goal was always a 48k system for several families. The only major components I have are a set of panels and my batteries. The inverter is a $10 yard sale thing. I was just trying to make our winter nicer on a budget. I don't understand how either the batteries or panels will make things difficult for me. It seems to me the middle part is the trickybit. The batteries will eventually be wired into being 8 48 volt batteries. And I will eventually get a 48v inverter/charger. I guess all the head shaking lets me know I just have to be patient. I have no desire to tear up batteries. I am currently only using three of the batteries. Perhaps that is what I wi continue to do. The thirty five amp charger seems to have no problem keeping them charged.
  • HamishHamish Registered Users Posts: 5
    Re: Help needed: who can rock the ad hoc?
    Photowhit wrote: »
    Where are you located?

    I think small deep freezers run around 1/2 Kwh a day, likely do able on a small system, and if you load shift and run the washer during the day you could likely run it on a small system, but your at the upper end of things and will need to monitor the State of Charge (SOC) and run your generator if your getting low, likely every over cast day. The bad news is both of these use a motor and you will shorten their lives if you run them on a Modified Sine Wave (MSW) inverter, particularly a cheap one.

    What is the VMP of your panels? if they are 24v panels (as 'Coot said around 35 volts VMP) then I would look to setting up a quick and dirty 24 volt system. I can point you to some inexpensive 24v used true sine inverters, but cheap means $300, I would be sure to get a charge controller that will work with a higher voltage system, so you won't waste money and just have to replace it in a year when you upgrade to a higher voltage.



    I am not sure about the panels vmp. I was td they were 12 v panels when I got them. Good idea on controller. Kind of what I was thinking. I got the panels from some org upgrading their grid tie system from 2k to 10k. I think part of their issue was 12vdc. I will check them out and post results
    Tomorrow. It's snowing here in the Catskill mountains, a d that means chores on a farm

    Thanks for all your help.
  • PhotowhitPhotowhit Solar Expert Posts: 5,658 ✭✭✭✭✭
    Re: Help needed: who can rock the ad hoc?

    It's a forum, you will have people how don't read carefully, and give poor responses. You will have others who are trying their best to help. If you are near by, I will lend you an inverter and charge controller and likely help you set it up!

    So if you'll tell us what the VMP of the panels are, and where you're located, perhaps we can help you out.

    If not, you may still learn something that will help you out in the future! If you have a VMP of 22-30 volts, you will need a different type of charge controller than if you have a vmp of @35. "shuoco 165w" didn't come up in any search...

    I did find 'Schuco' panels and these Schuco in 165 watts. They have a VMP of @23.4 volts which would work well for 48 volts in strings of 3 with a cheap charge controller. They will not work well for a 24 volt system, but since you have quite a few you could waste energy and use them with a cheaper PWM charge controller.

    As 'Coot suggested a C40 might work for all these, please note that since you would be at such a high voltage for 24v system, in strings of 2 panels, you might find most cheap 12/24v charge controllers would be fried (like the others in Xantrax/traces 'c' series, though they aren't cheap) The C40 will charge a 48 volt system.

    If you are in a sunny location, like the south west you can do a lot more with a small system than if you're in the Ohio river valley or the Pacific Northwest.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    Re: Help needed: who can rock the ad hoc?

    It is almost impossible to "grow" a system from small to large... Sort of like growing a VW bug into an eighteen wheel semi.

    There are some components that (usually) can be moved from smaller to larger systems... Those would include solar panels and higher end solar charge controllers (they will charge 12/24/48 volt battery banks).

    You have given us a mix/wide range of available hardware and a very small budget.

    The "problem" with the panels (if these are the correct ones):

    http://www.posharp.com/s-165-sp-4-solar-panel-from-schuco-international_p1597346918d.aspx



    STC Power Rating Pmp (W)

    165


    Open Circuit Voltage Voc (V)
    29.7


    Short Circuit Current Isc (A)
    7.73


    Voltage at Maximim Power Vmp (V)
    23.4


    Current at Maximim Power Imp (A)
    7.06


    Panel Efficiency
    11.9%


    Fill Factor

    71.9%


    Power Tolerance
    -5.00% ~ 5.00%


    Maximum System Voltage Vmax (V)

    600



    Is that they are Vmp~23.4 volt panels. This voltage is a bit "high" for charging a 12 volt bank (you will lose a fair amount of panel energy if using a "cheap/simple" PWM charge controller--You will get ~75% of the available "wattage" from one of these panels connected to a 12 volt battery bank through a PWM charge controller)).

    And they are too low for charging a 24 volt battery bank (which needs Vmp-array in the range of ~35-40 volts for efficient battery charging with a PWM controller.

    So, the normal solution would be to put several panels in series (to give Vmp-array higher), and those strings in parallel connected to a MPPT type solar charge controller--Which are much more expensive (~$300-$600+ for higher end/larger units). These MPPT controllers can take high voltage/low current solar array power and efficiently "down convert" to the low voltage/high current needed to charge the battery bank.

    So, we now start playing games... If you got the panel for little money, then you may be willing (at least for now) to toss ~25% of their power away and use a cheaper PWM charge controller--Perfectly good solution (with the right PWM charge controller).

    Next--Battery bank voltage. Remember that Power=Voltage*Current. If you change the battery bank voltage from 12 volts to 24 volts, your charging sources and loads will have to work with ~1/2 the current. Move up to 48 volts, and 1/4 the current of a 12 volt battery system.

    Means smaller diameter (gauge) wire, larger solar array supported on a charge controller (one 60 amp charge controller could manage a 4x larger wattage array on a 48 volt vs 12 volt battery bank--major cost savings in controllers and copper wiring). (note that power usage is the same--You will not save on gasoline charging the battery bank, and 48 volt systems are slightly more efficient in some ways, but can be more costly--There are few "smaller" 48 volt based AC inverters--So you may end up with a larger system than you really needed--at least as a starting point).

    The batteries--Big difference if they are UPS/float service rated AGMs vs deep cycle AGMs.

    Float service AGMs be "killed" by a few dozen deep cycles (taking 25-50%+ of the stored energy). Deep cycle batteries will last 100's to several 1,000 cycles in this type of service. Many UPS systems replace batteries every ~2 years or after major outages/deep cycles because of this (and there are a lot of "free" float service batteries out there).

    Also, it is difficult to make a large AH rated battery bank with lots of paralleled "smaller" AH rated batteries. Batteries do not "share" current well. You put 10 batteries in parallel, some may supply way more than 1/10th of the operating current (or charging current) and others may take well less than 1/10th the current. Wiring is critical (wires need to be the "same length" between parallel battery strings--equal resistance; batteries need to be matched in age/condition/brand/model/chemistry; and you need to monitor closely the bank for open and shorted cells/miss matched voltages/etc.).

    My humble recommendation is one series string of large AH batteries (typically in 6 volt/4 volt/2 volt cell configurations)--With 2-3 parallel strings being the practical maximum recommended for most people.

    AGMs are nice batteries and the "almost perfect" lead acid chemistry battery. However, if they are the wrong type (float service) or of mixed/unknown condition/age, you will be out there weekly monitoring your battery bank looking for poor performing strings/batteries. And replacing individual batteries once every month or so (possible--just really do not know).

    I like to start with a few different "paper designs" to help figure out what makes the best configuration (price/performance) for your needs. We can do this based on your loads. Some rough numbers:

    1,000 WH per day (30 kWH per month)--Small cabin with LED lighting, laptop computer, small fan, small DC water pump, cell phone charger.
    3,300 WH per day (100 kWH per month)--Very efficient home. Above + full size Energy Star Refrigerator, well pump, clothes washer. Good size DIY project
    10,000 WH per day (300 kWH per month)--Pretty much a normal very efficient home. About the largest off grid system that a "normal" person could afford.
    33,000 WH per day (1,000 kWH per month)--Average North American energy usage for home (some AC, electrical cooking, etc.)

    Or, you can pick based on how many solar panels you have... Or how many batteries you can make into a pratical battery bank (say 3 strings @ 48 volts would be a 300 AH @ 48 volt battery bank). Or how much you want to spend in this first phase, or something.

    At this point, I really do not have a good idea. If I suggest a small 300 Watt system @ 12 volts with 3 of your 12 volt batteries in parallel--Will that even meet your basic needs?

    Or would you want to go with a $1,6500 3.0 kWatt 48 VDC AC TSW inverter/charger and a $600 Solar charge controller (plus wiring, racking, breakers, etc.).

    I would still like to understand your needs/limits better.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Help needed: who can rock the ad hoc?

    You really have a bit of a problem. Lots of pieces and it wont quite fit together well. Hmmmm..

    OK, my solution would be go for a 24V setup, so you will need an MPPT type Charge controller and a 24V inverter, this way you can use 6 of your batteries with 3 parallel strings of 2. 3 is the max number to minimize charging problems, some have used more and seem to be OK but they are 'on top of things'.
    Get the best equipment you can afford, it will pay for itself many times over. The 'best' will depend on your system design! Which is based on the loads you want to run.

    Wrinkle: If you are running DC LEDs they will need 12 volts... otherwise use 110V. I have used both types. For DC I used track lighting fixtures and removed the small transformer (120 to 12v)

    Now have 24 volt system so using 120V AC for ease of wiring etc.. My favourites are these at Costco. http://www.costco.ca/Luminus%C2%AE-LED-B11-4.9W-Dimmable-Light-Bulb.product.100100933.html Ours come in a 3 pack for < $20
    Amazingly bright for only 5 watts.

    If you are worried about other TINY houses, 120V goes a long way and only the total peak loads are your pinch points... perhaps 2 inverters? one for a central freezer another for the lights?
    If you are going 48V for sure, buy a CC like a Midnite Classic with a WBjr shunt meter... and an Inverter -Charger if you are going to have grid or generator power.

    Lots to consider.
    hth
     
    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
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Help needed: who can rock the ad hoc?

    I understand that you are on a budget, and house building creates heavy demands on your time and money. But anyone building a RE power system is taking on the responsibilities of a power company. Amongst those responsibilities is to not kill anyone, and to not burn down anyones home.

    The minimum correct fusing and cable alone for a 2kWp system will run to over $500. So money IS required. And so is a certain level of knowledge.

    Ok, having got that out of the way. My advice is to be patient. Spend your time learning, and saving, then when you are ready, go for it. I get that you have panels and batterys, but that only gets you about half way.

    For a temporary system, well, lets look at what you have. More or less unlimited pv, and batterys, relative to your loads and other resources. So, i agree with whoever mentioned a Xantrex C40/C60, or the similar Morningstar TS40/TS60. They are cheap and cheerful PWM controllers. Here it doesnt matter if the PV isnt running optimum. Stack up as much PV as the controller will take, connect as much battery as will result in a peak charge rate of 0.2C or so. If you are wedded to the 10 buck yard sale inverter (which for the record i think is folly) then your temp system is 12v. That means for a 60 amp PWM controller:

    Max PV = 60 amps * 12 volts = Approx 720W.

    With PWM you dont want to overtax the controller, they dont self limit too well, so the derating loss should gives us a bit of lee way there. (fuzzy logic worth checking)

    For the battery: 60 amps peak , to get 0.2C that means the max battery is:

    = 60A / 0.2 = 300 Ah. (3 single batterys in parallel)

    So thats all of your pv and battery that you can safely hook up to a 12v 60 amp PWM controller. These numbers are a bit squishy, and worth checking. You should be able to get second hand PWM controllers for peanuts. But as i said strongly recomend you spend what money you have on breakers and cable protection.

    Later.... you have lots of batterys, and are planning on servicing 3 households, thus the greater the system voltage the better. Thus 48V is the only sensible plan mid term. Forget any kind of jump via 24V. So 48v system, 2 battery strings max (even thats a bad idea and will require careful management), thats about 200Ah at 48V. That will support about 2.5kW of PV. So the most of those batterys that make any sense keeping is 8. The reality is they arent a suitable battery for RE system, at least not a big one. Because they are too small. Big systems need bigger batterys.

    If i was you, id forget that inverter, or if you can stretch to it many here have found excellent deals on samlex inverters under $350. They are semi acceptable quality for home use. But really what you are looking for is UL listing for hardwire. Thats the only permanent solution for insurance and peace of mind purposes.

    Otherwise in the mean time run as much as you can off 12v. I bought some of these 12v LEDs recently and they are very cheap for ok quality. http://www.ebay.com/itm/High-Power-Cree-E27-MR16-GU10-LED-COB-Spotlight-Downlight-Bulbs-Lamps-6W-9W-12W-/261532368087 (note that the output is mistated, the "6W" ones are 3W, the "9W" ones are 6W, etc. Otherwise ok built.

    Please take care, and be patient.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • PhotowhitPhotowhit Solar Expert Posts: 5,658 ✭✭✭✭✭
    Re: Help needed: who can rock the ad hoc?

    I forgot to ask/mention, you said you had 3 batteries in the camper system now that you charged with the generator? So are you using the inverter with this or is there an inverter currently installed in the camper to utilize this stored energy or are you just using it as 12 volt? I would look to charge these batteries with the solar not to introduce a completely new system. This should save you some generator run time and money right away.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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