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Dead battery showing 5v - recoverable?
Dangle_kt - 5/11/12 at 05:11 PM

Hi,

Wondering if any of you guys know if a 12v battery reading 5v will charge or not.

Track day tomorrow, just went to start it up, and its dead. Got it on charge, but if I dont run soon I won't make it to halfords before it shuts - so....

will it charge or should i buy one?

Thanks

fullpint - 5/11/12 at 05:29 PM

If I were you I would try in now just to see if its started to charge. If not go get a spare. Not worth turning up for a track day only for the battery to fail...
Keep the receipt and if yours is ok just pop the new one back to halfords for a refund

ian locostzx9rc2 - 5/11/12 at 05:30 PM

I doubt it Ill be off to halfords

Dangle_kt - 5/11/12 at 05:38 PM

quote:
Originally posted by fullpint

Keep the receipt and if yours is ok just pop the new one back to halfords for a refund


Now that is a cracking idea!

At £55 I don't fancy buying one when I don't really need it!

fullpint - 5/11/12 at 05:39 PM

Simple really. They can't say no if you don't use it Its a win win situation..

vanepico - 5/11/12 at 07:26 PM

I fly RC planes and we are told if you take the Lithium polymer batteries below a certain level they are fubar'd. What you can do is fool the charger into charging it anyway to maybe 50%, by setting it to nicad/nimh, then at that point you switch the charger back to li-po cells and charge the rest. It worked for me once.

(They say this normally only works if it was a slow discharge)

Maybe this technique will work with car batteries but to be honest I'd rather spend a bit of money than be stuck at the side of a road, maybe keep a battery in the car as a spare if you try it.

Have a nice day,
Pete

Dangle_kt - 7/11/12 at 07:47 PM

It worked great! And I now have a receipt and £55 heading back to the orange place.

Thanks

PSpirine - 7/11/12 at 08:04 PM

I've recovered batteries that were at 0v for weeks, and they eventually worked absolutely fine and lasted years after that.

Equally I've had batteries that drained to 6v for about a day and then could not be saved - it all depends on the state of the internals.

I'd just put it on charge for a few days with an automatic charger (which will trickle/cut-off when charged), then drive around for a while, put it on charge again. Then use as normal and monitor for a week or so - it'll be quickly obvious if it's not performing well (in which case it's probably dead permanently).

Halfords return policy is always full of win