Battery questions.........

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GreenV8S said:

Presumably it hasn't been running at 11A during that time, or you'd have boiled the electrolyte dry on the 'good' cells by now.

I still think it's a lost cause, but if you're determined to see some volts out of it and don't mind wasting your time I suspect your best bet will be to put a massive current through it for a fraction of a second. This is often enough to burn through the lead whiskers which are shorting the two plates together and allow the cell to start taking a charge again. Briefly connecting another car battery to it via heavy jump leads would be enough. I just mean a fraction of a second, not long enough to start smoking the leads, and if it doesn't work at the first go you're probably just making things worse (as well as damaging the other battery) by trying again.

Note that the two 'good' (it's all relative) cells are now in a completely different state to the rest of the battery so any current you put in to try to recover the bad cells is now overcharging (and damaging) the 'good' ones. The lower the current you use, the less damaging it will be.

It so happens i have another 12v battery sitting next to it which holds 12v but doesn't allow the car to crank.

So you say from the 12v battery connect + to - on the duff battery and so on? for a split second?.

[GreenV8S]

I meant connect plus to plus and minus to minus - for about a quarter of a second, using decent jump leads. If it works then a cell that was previously shorted internally and stuck at 0V will slowly start coming up to voltage if you trickle charge the battery. As I said before - if it doesn't work at the first try it probably isn't going to work at all.

[1083 Feedbacks]

GreenV8S said:

I meant connect plus to plus and minus to minus - for about a quarter of a second, using decent jump leads. If it works then a cell that was previously shorted internally and stuck at 0V will slowly start coming up to voltage if you trickle charge the battery. As I said before - if it doesn't work at the first try it probably isn't going to work at all.

I stopped charging for around 12 hours, did the jump lead connection like you said for a split second. Then started charging again, but it hasn't moved off 4.44v for approx 7 hours now.

I guess thats confirmation that its a gonna.