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Re: laptop battery cycling

On 28/05/12 11:37, Robert Holtzman wrote:
> For the record, I'm running a Lenovo T420i with a 6 cell battery.
> In the past I've been told that it's bad practice to run a laptop on 
> AC with the battery installed because it would cause reduced battery
>  capacity.

Your Li-ion battery will have a longer life if it's stored in a well
sealed plastic bag in the 'fridge with a 40% charge than on constant
maintenance (trickle) charge plugged into the laptop. Take it out of the
'fridge and fully charge prior to using. Keep it in the 'fridge state
when running on mains.

> This raises two questions.

At least :-)

> First, is it true that laptop batteries don't have overcharge
> protection,

No. At least in your case it's built-in to the battery.

> and second, how many cycles is a battery like mine good for?'

At least 300 depending on storage and use.

My T60 has the extended battery which still holds about 2
and a half hours performance time after 300 full discharges over 4-5
years - but it's usually kept in the 'fridge.

As a general rule you should have between 70 and 85% of the capacity
left after 200 discharges. Most manufacturers rate the lifetime at 3 -5
years and 300 - 500 discharge cycles (less if kept on full charge and at
higher temperatures).

You might find the following reference useful:-

Kind regards

Iceweasel/Firefox/Chrome/Chromium/Iceape/IE extensions for finding
answers to questions about Debian:-

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