Battery - small irritation

Kevin Gordon kgordon420 at
Sun Nov 27 07:16:16 EST 2011

On Sat, Nov 26, 2011 at 7:03 PM, Richard Smith <richard at> wrote:

> On Sat, Nov 26, 2011 at 11:24 AM, Kevin Gordon <kgordon420 at>
> wrote:
> > Hi:
> >
> > I have received a new XO 1.5, shipped with a battery S/N starting with
> 008.
> >
> > Over the past few days, I've noticed something a tad strange.  No matter
> how
> > long it's plugged in, the little charging  LED stays yellow.  However,
> the
> > frame battery indicator says "100%"
> The full stop condition for battery charged is when the constant
> voltage taper current drops below .12.  I suspect you have some sort
> of cell defect that keeping the taper current above that.
> Next time you are using the machine stop powerd and run olpc-pwr-log
> in a terminal (you can use it normally) and let it run down until it
> powers off.  Then remove the battery, power back up, run olpc-pwr-log
> again and then re-insert the battery.  Let it charge until you see the
> got to 100 and the 3rd and 4th column of numbers reach some sort of
> steady state where they don't change much.  Ctrl-C and then send me
> the file.
> FYI. Col 3 is voltage in uV and col 4 is amperage in uA.
> Darn, I did something else first.

Yesterday, before I left for the day, I figured what the heck, let me try
and load batman.fth and run the bat-recover command.  That started off
cranking about 30-35 uA, and the uAh was increasing by about 1uAh per
minute.  But when I left after about 90 minutes, the uA was seemingly
decreasing and was averaging  about 17-20 uA, and the uAh was now only
increasing by about 1uAh every 3 minutes.

When I returned this morning, it was running at about 1.2 uA, and the uAh
had stagnated at 98.75. (The routine was running in total for about 14

The indicator was still yellow.  I removed the battery ( to get the
keyboard back ) when I reinserted the battery and .... the led turned
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.



> Thanks.
> --
> Richard A. Smith
> One Laptop per Child
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