Thread: Battery fully flattened - recharge or don't bother ?

If it's less than 2 years old, recharge it.

A flooded wet cell battery may recover after a flattening episode. You need either a solar panel without a regulator or an old fashioned non regulated battery charger. Leave it connected until the battery is gassing freely, then disconnect and see how it lasts. Do this in a well ventilated area of course away from stray ignition sources.

recharge it, what do you have to lose?

What ever you decide to do with the battery first of all check if the alternator is working properly cos an alternator with failed rectifire drains down any battery with ignition off and can kill a new too one in no time while running... be aware

Have done the recharge on old style battery charger trick before with deeply drained batteries (<5v). The ones that recovered worked, but their capacity was never the same.

OK folks, thanks for the replies.

As I've only got a trickle charger , I've put it in the 2nd battery position where it will receive the full alternator output of 14.4v for short runs over the next few days and then we will see how it holds it - I take your point Ric1970....

and sierra, I will keep an eye on that rectifier situation, although I doubt it would have been drained if I hadn't left a few things "on" for such a long period.

I shall report back in a few days

Originally Posted by 87County

As I've only got a trickle charger

That should be OK. What you don't want is an auto charger because it won't look at a deeply discharged battery. Once you've got some charge into the battery, an auto charger will work.

I think the first question should be - "How old is the battery and how well has it been maintained?"