OT : Laptop battery

[Stefek Zaba]

They don't take very kindly to going as flat as this one's likely to be: there's a possibility that one (or more) of the cells will no longer hold charge, having become reverse-polarised. Unlikely to blow up when you put it on charge, though, so suck-it-and-see (assuming you still have the relevant charger!) is fair enough. For future reference, it's better to put unused 'spare' rechargeable packs on charge a couple of times a year than to leave them in their Original Packaging...

[T i m]

Could it be 'Presario' ?

Had it been charged now and again it *could* still be useable. If it hasn't (and if it's still in it's packaging the chances are it hasn't) then it could be shot. ;-(

The only real test is to charge it up (it might say 'charged' very quickly) then run it flat (would be just a few mins). Charge it back up again and see it it takes longer (then discharge it again) and so on. It *could* pick up at last long enough to put it on eBay as 'working' ;-)

All the best ..

T i m

[JoeBhoy]

sorry - I know it's OT but you guys seem to know all sorts of sh*t (-;

I have an old Compaq presarion laptop battery which is still in the packaging. I was wondering - is there a time limit to how long these things can keep - this ones about 5 years old. Mint condition though.

cheers

Joe.

[John Stumbles]

Not saying you're wrong, but how would it get reverse polarised if it hadn't been on load? (I'm aware that the first cells to discharge in a battery on load will get reverse-charged by the other cells until the whole battery reaches equilibrium.)

AIUI NiCds are quite happy about being in a disharged state for extende periods, unlike Lead acid which sulphate up.

[Stefek Zaba]

err, mumble, little conductive green elves linking arms between + and - terminals, maybe? umm, maybe, mumble, when first plugged into the charger? um, mumble, creeps away...

I still wouldn't be surprised to find an unloved, discharged, multicell battery to have lost most of its capacity when left at the back of a cupboard for several years, rather'n having been tickled into holding charge a few times in that period. But I'd welcome correction from anyone with more knowledge; hmm, maybe that new-fangled Berners-Lee InterWeb thingumy has something to say? Lessee... there's a semi-authoritative-seeming NiCd FAQ at

suggests NiCds are optimally stored long-term discharged, cold, and shorted - but the NASA-quoted proceedcakes there require access to each individual *cell*, not just shorting the whole battery! Panasonic's guidelines at (on p.2) that batteries should be charged once or twice a year when being stored long-term, but other manufacturers - according to a collection of quotes at are less paranoid, though all agree that several charge/discharge cycles are likely to be needed after long-term storage to restore something like the initial capacity.

Isn't the infosuperhypenetwebway just wunnerful? ;-)

Stefek

[Dave]

I like to read your sensible postings, but I have to ask...

As it has never been charged, how can it go flat? The OP does say that it is in its original packaging, so...

AIUI a NiCad pack that has never been charged just requires conditioning and it will be happy to work for another 1000 (?) charges, or 2 years tops, of use.

HTH

Dave

[Stefek Zaba]

- which, as you point out, are a strict subset of all my postings ;-) Thus:

yes, I guess keeping it in its original, as-shipped condition is about the kindest way you could store it, ass-U-ming it wasn't 'test charged' before shipping or some such

More like than not! Thanks for the gentle use of cluestick...

[JoeBhoy]

That was my plan - stick it on Ebay - I just don't have a presario....

don't want to do it though if they are goosed!

cheers Joe.