Battery - small irritation

Richard A. Smith richard at
Sun Nov 27 13:15:28 EST 2011

On 11/27/2011 07:16 AM, Kevin Gordon wrote:

> GREEN.  I then went to my email, and alas then saw your procedure. Sorry.
> So, I have put a little tape indicator on the battery, and if it
> misbehaves again, I will instead run what you sent me.  (Unless you
> think it still instructive to  perform that test, but I fear my dabbling
> may have trumped the evidence.)
> Thanks for your quick reply, sorry I didn't get to it first to provide a
> better analysis.

No worries.  That suggests that your cells were out of balance.  How 
long was the longest you ever let it sit before running bat-recover?

In theory just sitting there (yellow LED) waiting for the taper current 
should be able to balance as well.

If you are experiencing balance issues I wonder if you have any reduced 
capacity to go along with that.  You can check that with olpc-pwr-log. 
The procedure would be to stop powerd; insert the battery on ext power 
and make sure its full; run olpc-pwr-log and then remove external power 
right when you see the first line of output.

Then you just want to let the laptop sit there idle until it shuts off. 
  Unless you have an old build olpc-pwr-log tracks the net ACR in the 
8th column.  Its in uAh.  The range I use for "good" is 2800000-3200000 
uAh.  If your olpc-pwr-log is old enough that it doesn't have a net ACR 
column then you can compute the value by subtracting the Full ACR value 
in 6th column on the 1st line by the value in the last line in the log file.

Richard A. Smith  <richard at>
One Laptop per Child

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