Batteries - slight amp hours/volts change

abrockca
abrockca Solar Expert Posts: 72 ✭✭✭✭
in Solar Beginners Corner #1
I admit I'm getting a little paranoid after my last set of batteries had issues ... so this question may be premature, but wanted to ask.

I have a new set of batteries. Working great - Rolls S-1380. Haven't run the generator except when we had a couple cloudy/rainy days and amp hours used got to 250.

But here's my paranoid question - when we first got them, we would be at 25 or 25.1 volts when we were at amp hours used of 140. The last couple days, at that same amp hours used, we're at 24.9 or 24.8 volts. We were pulling 8 or so amps, we're now pulling 9 amps.

Should I worry? Should I do an EQ? Rolls generally says only do an EQ every 3 to 6 months, and I've only had them for a couple weeks. But they weren't properly charged when they got here. And I apologize, I didn't check the SG before posting this; will try to do that this afternoon or tomorrow afternoon.

Anne
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Comments

  • bsolar
    bsolar Solar Expert Posts: 103 ✭✭✭
    #2
    Re: Batteries - slight amp hours/volts change

    heres a newb answer heh :) .. take it with a grain of salt and let the experienced guys tell you, but my guess is the 8 160w panels aint quite enough for a 12 cell bank .. i have about the same rated panels but 12 panels on an 8 cell bank and that seems matched fairly good. My bank fluctuates alittle depending on usage, i doubt theres a problem on yours myself .. i would probably add about 6 more of those panels though, but really, im not the expert here ... ;) oh nevermind i see theres two arrays heh .. i think its normal, probably just using the gen, if usage is the same and the charge is the same everytime it will probably level out ..
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #3
    Re: Batteries - slight amp hours/volts change

    At 2780 Watts total, your array is a little more than half the size it needs to be for a 1380 Amp hour 24 Volt battery bank. So the questions are: does it reach Absorb Voltage level (should be 28.8 Volts)? How long does it stay in Absorb (should be 2+ hours)? Don't know what kind of battery monitor you've got, but it can take a bit of fiddling with them to get them programmed properly.

    Obviously you already know that checking the SG is more important than Voltage levels or watching the Amp hours.
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,485 ✭✭✭✭
    #4
    Re: Batteries - slight amp hours/volts change

    If they were not fully topped off with sufficient absorb period you cannot compare discharge cycles.

    You don't have to top out every day but you should try to get a full absorb period in at least every 3 or 4 days to get full capacity back.
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  • abrockca
    abrockca Solar Expert Posts: 72 ✭✭✭✭
    #5
    Re: Batteries - slight amp hours/volts change

    I am getting through bulk/absorb (set to three hours) and into float most days... but yeah, probably should do an EQ soon. And probably shouldn't worry so much either...

    thanks for the thoughts!

    Anne
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