Archived from groups: comp.sys.laptops (
More info?)
Chip Orange wrote...
> Barry Watzman wrote ...
> > I'll bet that you left it in the laptop while the laptop was almost
> > continuously connected to AC power, right?
> >
> > That kills batteries due to overcharging and heat.
> >
> I didn't think this theory as widely accepted?
Overcharging isn't a normally problem with Li-ion batteries: they vent
hydrogen when overcharged- generally as a sheet of flame! Hence laptops
must have a very good battery management circuitry that prevents
overcharging.
Temperature is another matter - the higher the temperature the faster the
inevitable loss of capacity. Most manufacturers advise storage in a cool
place - preferably at 40-50% charge if storage is going to be for an
extended period.
I have two batteries, which I keep out of the laptop when on mains power
(unless I'm doing something critical like a BIOS upgrade where loss of power
would be disastrous). I keep one battery fully charged and the other at 40%
and top it up when I need to take it on the road, periodically swapping main
and spare to give them both the same amount of use.
David