24V forklift battery has failed

softdown
softdown Solar Expert Posts: 3,915 ✭✭✭✭
in Off Grid Solar & Battery Systems #1
Showing full voltage I figured it must be the inverter that caused the power outage to three freezers. But the new inverter failed to roar to life.

Battery shows resistance over 14 on one side and only 222 CCA. The other side has resistance over 9 and about 340 CCA. Really dismal figures. The cap on a cell had disappeared and the cell went pretty dry while I was gone for about 1/2 year. About half the cells no longer use water - meaning they are pretty well dead in my book.

It was an interesting experiment. Good thing I have a couple large Fullriver 12V solar batteries to connect pretty soon. Good thing I noticed the freezer area seemed off and checked. Imagine if this happened while I was gone for ~ 1/2 year.

Interesting that my power alarms failed to sound. They must have worn out their batteries when I had a low battery power outage while away.
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • softdown
    softdown Solar Expert Posts: 3,915 ✭✭✭✭
    #2
    Having lost weight and gotten older, carrying a Fullriver is all I can do. Mostly drug them around this time. When I bought them I carried ten of them around (seperately) on two occasions. Something to keep in mind when buying lead acid batteries.

    Now I forget the proper size cabling for connecting the batteries serial (24V) and connecting to 1500 watt inverter that rarely supplies more than ~500 watts or so?

    Wrong side of 50 was one thing. Wrong side of 60 is another.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • 706jim
    706jim Solar Expert Posts: 520 ✭✭✭✭
    #3
    You can connect the inverter with #4 wire. I originally set up my Trace DR1524 2ith #1 wire, but honestly #4 will work just fine.
    Island cottage solar system with appriximately 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing due south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter which has performed flawlessly since 1994. Outback Flexmax 80 MPPT charge controller four 467A-h AGM batteries. Insignia 11.5 cubic foot electric fridge 1/4hp GSW piston pump. My 31st year.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,622 admin
    #4
    For wiring size--This simplified NEC chart is a good start (and pretty conservative):

    https://lugsdirect.com/WireCurrentAmpacitiesNEC-Table-301-16.htm

    You can use this voltage drop calculator... Suggest:
    • 12 volt bank: 0.05 to 0.10 volt drop from charger to battery bank (accurate voltage measurment) & 0.5 volt max drop @ max continuous current from battery to inverter/DC loads.
    • 24 volt bank: 0.1 to 0.2 volt charger drop & 1.0 max load drop
    • 48 volt bank: 0.2 to 0.5 volt charger drop & 2.0 max load drop
    For drop calculations, a simple voltage drop calculator will work:

    https://www.calculator.net/voltage-drop-calculator.html

    For actual DC current to AC inverter current--Use max planned power (10.5 @ 12 volt bank; 21.0 volt @ 24 volt bank; 42.0 volts @ 48 volt bank):
    • 500 Watts * 1/0.85 inverter eff * 1/21.0 Volt min batt voltage = 28.0 Amps max current @ max sustained load
    Note the above assumes that you will have a surge current support of 2x max AC load and/or 2x max inverter Wattage rating.

    Forklift/Industrial Traction FLA batteries tend to use more water when charging (detailed chemistry of cells) and usually have less reserve water reservoir for industrial batteries vs "solar battery" design. So at least weekly electrolyte level checks -- At least until you can safely justify monthly level checks.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • softdown
    softdown Solar Expert Posts: 3,915 ✭✭✭✭
    #5
    Unsure about a new thread about the latest developments:
    Accidentally tried to hook up a 12V Cotek inverter - did not know I had a 12V. Wound up hooking up the old 24V Cotek which is working fine.

    But the Renogy charge controller is now lights out. This is not the first time it has been silenced while I messed around with wiring. I am hopeful it will come back to life. Measuring over 42 volts of input current to the charge controller. Pressing the ON button does not work. Ideas?

    Solar equipment is just too delicate. One spark and stuff dies. One seemingly has to follow a perfect sequence to avoid any sparks.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • softdown
    softdown Solar Expert Posts: 3,915 ✭✭✭✭
    #6
    Forgot to hook up the CC to the inverter. That is why the lights were out.

    But several years of sitting has taken a toll on those once premier batteries. They discharge and recharge too rapidly for my tastes. Perhaps being in actual use will normalize this trajectory. As I recall these batteries are now 6 years old - though their self discharge rate is extremely low.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,622 admin
    #7
    Cycling the batteries "aggressively" is probably the only possible recovery (discharge/charge/EQ cycles).

    For the charge solar charge controller--Disconnect the solar array, disconnect Vbatt, and let sit for a minute. They 1) connect Vbatt first (check wiring--Is there Vbatt on the controller's batt terminals? Does controller boot/display become active), then 2) connect solar array second. And check the Vpanel input terminals have array voltage (checking voltage/connections/polarity).

    Might as well keep discussion in this thread.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • softdown
    softdown Solar Expert Posts: 3,915 ✭✭✭✭
    #8
    I suspect that if one feels no significant heat when touching the cable then the size is generally adequate. Ordinary household appliances can heat up the 16AWG wires they are frequently hooked up with. Plus we usually try to keep our solar connections as short as possible.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • softdown
    softdown Solar Expert Posts: 3,915 ✭✭✭✭
    #9
    Conundrum has presented. Tested a bunch of cells between 1.0265 and 1.0275 -  quite healthy. Two cells were too low on electrolytes to test. So I had to charge after filling to "stir in" the freshly added H20. Unless I find a bad cell the mystery has deepened.

    Then again, I do seem to witness a lot of very odd stuff.

    Perhaps the water level in one cell was simply too low? Never heard of that though. No cell took over ~20 ounces of water - by my wild guesstimation.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,622 admin
    #10
    Exposing plates to air (oxygen) is usually a quick death to the cell. The exposed plates quickly sulfate (from what I have read).

    You could always try a battery desulfator and see if that works or not (not a fan of desulfators--But may be cheap to try and see if works for you).

    Example of replacing a bad cell:

    https://www.youtube.com/watch?v=SMYQlbp1gzY

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • softdown
    softdown Solar Expert Posts: 3,915 ✭✭✭✭
    #11
    Gone for six months - most of the tops did get exposed. I bought the battery with all the tops exposed - about five years ago.

    The battery shows good voltage and great SG though. This board feels that SG is the Holy Grail of battery health. Though it is still possible to turn up a bad cell - two have yet to be measured.

    I have a suspicion the battery will be functional now that all plates are properly watered. Being short of water could have acted as some type of short - that is my current theory anyway.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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