battery best practices

[Lennart Sorensen]

On Thu, Jul 06, 2006 at 11:49:07AM -0400, Madison Kelly wrote:
>   I got a new battery for my aging laptop :). This got me thinking; 
> given that almost every day I use the laptop on batteries what would be 
> better for the long-term life of the battery:
> 
> - Fully discharge it before plugging it back in (one or twice a day)
> - Plug it in as soon as I can.
> 
>   The first option will prevent memory (it's LiIon), but the second 
> option doesn't draw on the battery as much.

According to what I have read, draining a lithium ion battery past about
40 to 50% is actually bad for it's life.  Charging it before it gets
that low makes it last longer.  It certainly does not have the memory
effect of older battery types.  It does have other characteristics
though.

For example from http://www.batteryuniversity.com/parttwo-34.htm it
says:
"A lithium-ion battery provides 300-500 discharge/charge cycles. The
battery prefers a partial rather than a full discharge. Frequent full
discharges should be avoided when possible. Instead, charge the battery
more often or use a larger battery. There is no concern of memory when
applying unscheduled charges."

The battery level measurement however does on some systems occationally
need calibration, which requires doing a full complete discharge.  I
have seen people claim they do this every 30 to 50 charges, to keep the
battery meter fairly accurate.

The page above is a great read for lithium ion batteries.

Len Sorensen
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