End Cells

ZoNiEZoNiE Solar Expert Posts: 100 ✭✭
My calendar reminds me to check my batteries every two weeks. I have two Costco purchased Interstate 216 Ah 6V GC2's. One is 2010, one is 2011 (Long story why they don't match). I noticed that the cells on the ends, basically the one under the positive terminal on the left battery and under the negative terminal on the right battery always need a wee bit more water than the rest. I am in Phoenix, It's summer, the batteries are in a black steel (Vented) box behind the LP tanks on my trailer tongue. Two theories:

1. They are at the terminals, so get more temperature changes due to loads?
2. They are on the outside edges, and the other cells are more insulated by the rest?

Just an observation. The Levels are not critically lower, or lower much at all, but there is a difference. They also measure slightly less with the Hydrometer.

I realize these are probably past end of life, but my Midnight Kid is treating them very gently. Waaaaay better than the WFCO charger that came with the trailer.


  • petertearaipetertearai Solar Expert Posts: 368 ✭✭✭
    If they have a lower sg then maybe more bubling on those 2 cells. Try an Equilize ?.
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . victron battery monitor . 24 volts 450 ah surette batterys . off grid  holiday home 
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    If they have a lower sg then maybe more bubling on those 2 cells. Try an Equilize ?.
    Wouldn't you expect bubbling with off gassing of hydrogen and oxygen but no acid mist discharge to result in a higher SG at the gassing cells?

    SMA SB 3000, old BP panels.
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