Help with seting over volt disc. and charge limit on MT50

13

Comments

  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    For a cell monitor I actually used a second BMS from Chargery, it's a passive type with external drives for contactors, probably a little overkill for strictly a monitor @$100, I do use the drives but won't get into that. The monitor you have also has cell ballancing, I wouldn't recommend using that as it may conflict with the BMS which has cell ballancing. This is what I use http://www.chargery.com/BMS16.asp   can't vouch for any others without experience, but whatever the choice make sure that it's passive.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Raj174Raj174 Solar Expert Posts: 794 ✭✭✭✭
    It's handy to have an AC/DC clamp meter. 4 decimal places will show accurate LiFePO4 cell voltage and the clamp can be used for measuring charge and discharge amps on the battery bank. This is the one I have, but what ever you get, make sure it will read both AC and DC amps with the clamp.

    https://www.newark.com/tenma/72-7224/multimeter-digital-clamp-3-3-4/dp/45M5525
    4200W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Thanks, guys for the recommendations.

    It has been 24hrs since I have been charging the cells in parallel with the 3.65v charger.
    they read 3.35v  It will prob take 4 days to fully charge
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    In general, Li Ion and Lead Acid batteries are very "Coulomb" efficient (i.e., 1 Amp*Hour in to charge the battery, you get 1 AH out when discharging the battery).

    FLA batteries are less efficient near end of charging cycle (>90% state of charge; Equalizing, gassing, etc. is not Culumb efficient charging; 1 AH in, less than 1 AH out or even near 0 AH out when gassing/EQ charging).

    So, if you have a 600 AH "1 cell/paralleled cell" battery that is 20% down or 20 AH down, and a 2 Amp charger then charging should take:
    • 120 AH / 2 amps = 60 Hours of charging (purely made-up numbers to demonstrate math)
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Raj174Raj174 Solar Expert Posts: 794 ✭✭✭✭
    If you have the 14 amp charger that mcgivor recommended, and charged for 24 hours, that would be 336 amp hours into the cells. Your cells paralleled create a bank that's 800 amp hours at 3.2V nominal. If they were anywhere close to 3.3 volts before charging they should have finished within 24 hours. So logically, they were 50% full or less when charging began or there may be a bad cell. The first post did show one of the cells over 4 volts, a definite no no for LiFePO4 cells. You could check by removing the charger and the buss bars, then check individual cell voltages. They should all be very close, within a few millivolts. You might want to charge them a little longer, but if the voltage doesn't climb consistently, I would check individual cell voltage. 

    Rick
    4200W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
     At 3.35V the cells are approaching a fully charged state, the charging current is reduced at this stage to prevent voltage runaway, the difference in capacity between 3.350 and 3.650V is very little, this is the knee of the charging curve.

     
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jonrjonr Solar Expert Posts: 1,386 ✭✭✭✭
    I agree with Raj - it would be wise to do some simple, brief load testing on each individual cell to check for bad cells.

    I am available for custom hardware/firmware development

  • projectileprojectile Registered Users Posts: 47 ✭✭
    Bill
    sounds like my 8 cells 3.2v to 3.65v 100ah each, which started to charger from 3.35v will take over a week to reach 3.65v
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Hi Raj
     an independent meter says they are all 3.28

    then a few days later I charged them to 3.33v and I checked each cell independently.
  • Raj174Raj174 Solar Expert Posts: 794 ✭✭✭✭
    The odd thing is, charging with 14 amps from 3.28V to 3.35V should only take an hour or two. They were charged for 24 hours. Where did all of that power go? Options: Keep charging in parallel or load test the cells individually. 
    4200W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • mike95490mike95490 Solar Expert Posts: 9,274 ✭✭✭✭✭
    Raj174 said:
    The odd thing is, charging with 14 amps from 3.28V to 3.35V should only take an hour or two. They were charged for 24 hours. Where did all of that power go? Options: Keep charging in parallel or load test the cells individually. 
    I'd say halt charging and start taking some precise (3 or 4 digit) voltage measurements of each cell before things start degrading.

    Li cells don't give much wiggle room for mistakes.


    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    edited August 2019 #75
    The charger is 14A but only when the voltage is low, can't remember the exact transition points, but the current begins  drops in the  >3.000V regon continuing to reduce as voltage increases. Having the ability and equipment to measure this it was of concern to me as I believed the charger was faulty. The manufacturer assured new that it was normal, the last stages took the most time as current dropped below 1A, mind you I had 4 × the capacity we're talking about here.

    Having the right equipment, a DVM that can measure to 1mA along with a DC clamp on ammeter are essential, anything less is guesswork, in much the same way as working on a new car without diagnostic equipment.

    Will pull out the charger and refresh my memory and post details when available.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    edited August 2019 #76
    Here are the results of my testing.

    Having discharged a cell to near 3.000V I connected the charger rated at 11A, below demonstrates the corrolation bet current and voltage. This continues as the voltage nears the fully charged state, so it can't be said, with this charger, that in 24 hours a given amount of ampere-hours went into the cell as it's not a simple linear calculation and the charger is definitely not constant current. My assumption is that when the cell voltage is at minimum 2.5V the charger would supply 11A, but I didn't want to go that low.

    Further I won't continue to charge because the cell is in storage, so I would have to discharge it for little gain in information, I do remember this being an extremely slow process, 3 days or 72 hours.

    3.005V - 9 2A
    3.145V - 5.5A
    3.215V - 4.2A
    3.233V - 4.0A
    3.252V - 3.8A
    3.268V - 3.6A
    3.275V - 3.6A  * This is where it will hold for a very long time, the level portion of the charging curve 

    Hope that this information is helpful, personally I think everything seems normal in the OP'S case, it's just a matter  understanding the charger, obviously more accurate information would help.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • projectileprojectile Registered Users Posts: 47 ✭✭
    HI guys
    I had unplugged my charger for a few days because of vacation holiday.

    I noticed that my charger was set to 220 ac volts for it to work.
    I just switched it to 110 ac volts and I can nowhere the charger running. 
  • projectileprojectile Registered Users Posts: 47 ✭✭
    mcgivor 

    Please help me connect the BMS.
    thanks
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    I am not sure what to say... If the power supply has a 115/230 VAC switch, here is an example circuit that shows the typical wiring and circuitry around the 115/230 VAC switch. The idea is that the intermediate high voltage capacitor is charged to ~380 volts DC peak in either case (115/230 VAC input voltage) depending on the switch setting (and line voltage). You can trace the power through the input state and see if anything is blown:

    http://danyk.cz/s_atx02d.png

    "Input line select, short for 115 VAC input"

    Obviously, if you are poking around inside the high voltage front end of a Power Supply, be very careful.

    Check for blow fuse/etc, a bad 115/230 VAC switch, etc. (I assume you never connected to a 230/240 VAC line?).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    HI guys
    I had unplugged my charger for a few days because of vacation holiday.

    I noticed that my charger was set to 220 ac volts for it to work.
    I just switched it to 110 ac volts and I can nowhere the charger running. 
    The switch is default set to 230V to prevent damage, if 110V were set and connected to 230V there would likely be some magic smoke released. Reading the last line above, should it read " I can now hear the chargerror running " ?
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    mcgivor 

    Please help me connect the BMS.
    thanks
    Have you completed the ballancing? 

    Wiring the BMS is as simple as following the wiring diagram below, all the BMS control is done on the negative pole, the only positive inputs  to the BMS are the individual cell positive monitoring wires, the B1 to B8 thin red lines.

    The battery negative thin black line is the black sence wire in the input connector supplied, it goes to the negative terminal of the series bank.

    The thick black line represents the battery negative output and should be sized appropriately for the maximum loads, I used a copper link between the terminals and a single battery negative cable.

    The individual cell positive sence wires, thin red lines, go to the cell positive terminals and MUST be in correct sequence exactly as the diagram shows. 

    The thick red line battery positive, which connect to the inverter positive input and controller positive output, there should be overcurrent protection in each which are not shown in the diagram, I used a bus bar close to the battery to parrallel connect the charger and inverter positive. Note the positive to inverter should be appropriately sized for the maximum loads.

    The thick black lines on the right are the inverter negative input, or discharge, the other is the charge controller negative output. All should be sized appropriately, again I commoned the terminals of the input and output with copper links, not essential but my recommendation.

    Some suggestions.
    Use some wire numbering in the positive sence wires to avoid mistakes like these

    Source some DC circuit breakers appropriately sized for the charge and discharge circuits. 
    Have some cables made with crimped lugs, welding shops are a useful resource for this.
    Take your time, don't rush or take short cuts, get all the equipment needed before hand.

    Please specify your maximum loads  and charging source capacity along with distance, hint keep as short as possible, if you need help determining the required conductor size.







    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Thanks, Mcgivor

    Ill source the parts this Sunday. 
    the cell are balanced
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Hi Mcgivor:

    I got really busy.
    My Batteries need to be balanced again and I have to connect the BMS.
    I will start to reread this thread again tomorrow.

    I hope you can still help me.

    Thanks
    Projectile




  • fratermusfratermus Registered Users Posts: 44 ✭✭
    Haven't read the whole thread, but PARA errors on the MT50 and underying controller are the result of having certain parameters set in excess of other ones.  The way to avoid this is to adjust the parameters in a particular order so you can see where the problem lies.
    2017 Promaster 159" DIY camper
    570W mono / 220AH GC
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Thanks fratermus
    I will check that out when soon
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Hi
    i have gone back to the step of balancing by batteries.
    I have 8    3.2v lipo4 100ah 
    i ran the batteries down to a total of 24.8 v
    I then check each battery. There are the readings. 
    1.     3.235v
    2.     3.206
    3.      2.869
    4.     3.226
    5.     3.141
    6.     3.198
    7.     3.097
    8.       2.833

    How long should I keep the batteries in parallel before the batteries will become equal in voltage or state
    of charge?

    I am not charging the until they are equal in volts. 

    Should I have discharged the batteries to 2.5v before connecting them in parallel?

    thanks 
    projectile
  • Raj174Raj174 Solar Expert Posts: 794 ✭✭✭✭
    You really didn't have to discharge them before connecting them in parallel. Just a few hours parallel before you start to charge them will do.. The cells will constantly be balancing while you charge them. If you're using a 3.65v charger, then just charge them until the charger shuts off. It can take quite a long time, days, so be patient.
    4200W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Raj174:
    Thanks
    I have them just sitting in parallel for the past 12 hours.
    Most of the cells read 3.105 or 3.104
    I will now use the 3.65v charger to charge them in parallel.

    Thanks again
    Projectile
  • Raj174Raj174 Solar Expert Posts: 794 ✭✭✭✭
    Sounds good
    4200W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    There are two different "balancing" methods... One is "bottom balance"--Discharge all the cells so that they are equal voltage... Tends to be used on electric cars so that if all of the energy is used, the batteries reach "empty" all at the same time... If you have some batteries "empty" and most "not empty", it is possible for the cells that have energy to "reverse charge" the empty cells (take to zero volts, then start charging with a negative voltage)--That is pretty much death to those cells/batteries.

    The other is "top balancing"--As I understand typically used on solar power systems... You want all the batteries to reach 3.75 volts at the same time... That way your when (for example 4 series connected cells) reach 3.75 volts, the entire bank will be a  14.8 volts and "full".

    If you have a few batteries at "low" state of charge, when you reach 14.8 volts, some batteries will be under 3.75 volts, and others will be >3.75 volts... Lithium Ion batteries tend to not like over charging--It will damage the cells... When you top balance, all the cells reach 100% at the same time, and the 14.8 volt charge controller can stop.

    BMS (battery management systems) can change things around... The simplest will measure the voltage on each 3.xx volt cell (or parallel connected groups of cells) and report if any group is over/under voltage (and can trip a relay or transistor to disconnect the battery bank). Other BMS can actually move charging current around--Bypassing "full cells" and letting current through cells that need charging.

    Li Ion batteries tend to track each other very well, and do not generally need active balancing by the owner or BMS for a long time (months or years?). Good cells tend not to drift from each other.

    For LiFePO4 batteries, tend to choose something like 90% as "Full" and 20% as "Empty"--The batteries tend to last much longer if cycled in that range (BMS can choose 90/20 percent as full/empty limits and "hide" the extra capacity from the user).

    You can run "naked" LiFePO4 batteries, or choose to implement some version of BMS. Whatever you do, there is some studying to be done to make sure that the BMS (or not) meets your needs and you operate everything correctly (for example a BMS may not "top balance" cells until you reach a specific charging voltage (aka "over voltage a bit")... If you stop at less than BMS trip point, the cells will not get their balancing by the BMS.

    Others here know much more about Li Ion and BMS--And how they interact/connect with charge controllers/AC inverters, etc...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • projectileprojectile Registered Users Posts: 47 ✭✭
    Hi everyone 
    Thanks Bill
    I have a Victron energy batter protect in my solar system that I want to run some light bulbs led, tv and computer.
     My understanding is that the Victron energy battery protect will stop my battery from being drained too much and stop it from being overcharged.
     I have set the Victron battery protect to A8 which should shut down power usage at 24V and starts a charging at 26.v
    i believe the charge controller stops the charging so that my battery does not get over charged.
    Do I really need another BMS for my system .?

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