Improving Laptop Battery Life

Archived from groups: comp.sys.laptops (More info?)

Kamal wrote:
> The last time I read and researched, the jury was still out on how to
> improve the battery life. Some said that if one is connected to AC
> supply, then the battery should be removed from the laptop. Others
> opined that battery should be in the laptop while connected to AC
> supply specifically to improve its life. Still others thought that
> laptop should periodically be run only from batteries and one should
> allow it to fully drain and then recharge. And finally another set of
> people claim that batteries should NEVER be allowed to completely run
> down as it reduces the life.
>
> What do you guys think ?

That you have accurately summed up the situation and that you will have
to make up your own mind!

--
John Doue

Archived from groups: comp.sys.laptops (More info?)

"Kamal" <kamald2002@yahoo.com> wrote in message
news:63f50435.0404280456.4a2ab2ab@posting.google.com...
> The last time I read and researched, the jury was still out on how to
> improve the battery life. Some said that if one is connected to AC
> supply, then the battery should be removed from the laptop.

This is because heat damages li-ion batteries, if your laptop puts out a lot
of heat near to the batteries (and most smartly designed laptops don't) then
you should remove it when you're not using it.

> Others opined that battery should be in the laptop while connected to AC
> supply specifically to improve its life.

Probably because of IBM's early speedstep laptops, since without the battery
they won't run at full speed. It's possible that they also meant that
leaving the battery out for extended amounts of time (especially a flat one)
will damage the pack and its capacity, which it will.

> Still others thought that
> laptop should periodically be run only from batteries and one should
> allow it to fully drain and then recharge.

What's meant by this is running a laptop down to only 50% ALL the time, will
mean that the battery can't calculate how much capacity has been lost from
all those cycles. Taking the battery down to 3% or so will help the battery
re-calculate its capacity properly.
Also if you only use the battery maybe every month or so, discharging
occasionally might help it to recalibrate itself properly.

> And finally another set of
> people claim that batteries should NEVER be allowed to completely run
> down as it reduces the life.

Yep, never run a battery pack down to below 0% unless it's not working out
its remaining capacity properly. If you can check the voltage output
(preferably using software) - once the voltage output of the battery drops
below its rated voltage (10.8v, 14.4v) then you will begin to damage the
cells slightly. Doing this repeatedly will really hurt the capacity on the
cells.

>
> What do you guys think ?

Ideally, just discharge the cells down to 10% or maybe a little less than
that when you have to. But don't worry about battery memory, flattening the
battery is completely unnecessary with a li-ion battery except for the
reason above. Just discharging it down to 20% and then recharging shouldn't
harm the battery.