Battery losing charge while off [Devel Digest, Vol 75, Issue 63]

Richard Smith richard at laptop.org
Fri Jun 1 07:32:44 EDT 2012


On Thu, May 31, 2012 at 12:41 PM, Yioryos Asprobounitis
<mavrothal at yahoo.com> wrote:
>
>
>
>>
>> On 05/24/2012 11:59 PM, Yioryos Asprobounitis wrote:
>>
>> >> laptop serial number.   Was it a
>> >> pre-production XO-1 ?
>> >
>> > Both XO-1s used to test the battery are C2 machines
>> > #CSH7470023EA
>> > #SHF80701C99
>> > The batery in question is
>> > #00802091012110003588
>>
>> So let me review and see if I have all the details.
>> Seems like each new
>> email has more new details.
>>
>> - Battery does not lose charge outside the laptop.
>> - Tested the battery in 2 different laptops and the loss is
>> the same.
>> Roughly 12% overnight.
>> - A different battery in those same laptops does not lose
>> 12%
>
> Correct in all 3 (but ~12% in a 24h period)

Ah... 24 hours... Looking back you said that in the original email.
So 12% is about 370mAh which at the nominal battery voltage should be
2.2 to 2.5 Wh.  Over 24 hours that a draw of 90 to 100 mW.  Thats high
for the EC not going to into stop mode but perhaps there's enough
error in the measurement to skew the results.

My 1st guess is that something in the battery EEPROM is making the EC
unhappy and its not going into stop mode when the power is off.

Put the funky battery in the laptop and boot it.  Then stop at OFW and
do a 'bat-dump-banks'. Then send on the output.

-- 
Richard A. Smith
One Laptop per Child



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