Keith,
Open circuit voltage readings can be misleading, though the numbers you quote appear good (25 amp-hrs sucked out of a battery, then measure voltage). Voltage under load gives more info... too bad we can't measure cell voltage, only whole battery voltage. That is where LiFePO4 batteries with a BMS excel (measuring each cell all the time).
I'm still learning about batteries, and hope to provide some quantified results from my desulfator experiments. I think a completely discharged cell has nearly all water and no sulfuric acid remaining... a very difficult situation to recover from. Swapping electrolyte is probably a last resort in trying to restart the chemistry. Perhaps the sulfur ions are locked up in lead-sulfate crystals, depriving the electrolyte of their chemistry.
Mark Stafford
--- In electricboats@
>
> I'm still tracking down a gremlin in my battery pack and have a strange one.
>
> One of my batteries reads a more-or-less normal voltage. But a specific gravity test reveals 1 cell which is basically water. How can that happen? I moved some electrolyte around between cells and it gave a brief improvement in total voltage.
>
> Is this a short? I thought that would drop total voltage?
>
> Could it be a cell-reversal? That should lower voltage too, right?
>
> Why is the voltage near-normal (open-circuit reading 12.14 after 25AH discharge)
>
> the cell-to-cell voltage is also erratic.
>
> Basic symptom that started it all is that this battery is 1 of 2 in the pack that show lower-than-normal voltage after a moderate discharge.
>
>
> Any help from the battery wizards appreciated.
>
> -Keith
>
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