Laptops / Games / Fedora & battery life
M.Hockings
veeshooter at hockings.net
Mon Feb 9 16:52:51 UTC 2004
> On Sun, 8 Feb 2004,
>M.Hockings wrote:
>
>
>
>>I think that most modern laptop batteries are "smart", that is they have
>>a chip that tries to keep track of the battery's available power. If
>>you don't completely discharge the things once in a while they kinda
>>forget about the rest of the battery. Going from memory I think the way
>>to recover some of the lost capacity is as follows. Power off the
>>machine, then power it back on to the power on password or hold it in
>>the bios setup or whatever until the battery completely dies. Then plug
>>it in and let it completely charge. That should help calibrate the
>>chip. I seem to recall reading in the specs for one laptop about how
>>long the battery would last when new and how long when 1 year old. It
>>was diminished by a significant amount.
>>
>>Mike
>>
>>
> Joel Jaeggli wrote:
>
>Batteries wear out. discharging lithium-ion or polymer batteries to the
>end of their usable charge is a good way to damage them faster...
>
>to quote some motorola engineers:
>
>The relationship between DOD (depth of discharge) and cycle life is
>logarithmic. In other words, the number of cycles yielded by a battery
>goes up exponentially the lower the DOD. Research studies have shown that
>the typical cellular phone user depletes their battery about 25 to 30
>percent before recharging. Testing has shown that at this low level of
>DOD a lithium-ion battery can expect between 5 and 6 times the cycle
>numbers of a battery discharged to the one hundred percent DOD level
>continuously.
>
>http://www.motorola.com/ies/ESG/testlab/article1.htm
>
I did not say to do it continuously, just as a way to reset the battery
chip.
I believe that the recommendation with IBM Thinkpads is to do it monthly
though I can't find the doc right at the moment.
Mike
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