Power LED not switching to green even when fully charged

Richard A. Smith richard at laptop.org
Thu Nov 26 23:59:39 EST 2009

> On Thu, Nov 26, 2009 at 9:12 AM, Daniel Drake <dsd at laptop.org> wrote:
> > On Thu, 2009-11-26 at 09:08 +0000, Christoph Derndorfer wrote:
> > >
> > > Odd, after running down the battery yesterday I again charged the
> > > machine overnight and this time the power LED was green in the
> > > morning. The only difference between those two charging sessions was
> > > the yesterday I had used the black generic AC adapter whereas tonight
> > > I accidently used the normal green XO-1 adapter.
> >
> > That's a big difference. Maybe you could re-run the test again another
> > night using the black adapter.
> Okay, will do:-)

Indeed there is a big difference in how hard you can charge the battery.  A mistake in the power limit circuit on a B2 allows it to draw up to 34 Watts.  The generic black adapter has the ability to supply this much power where the green XO-1 adapter does not.   

There are several physical parameters of the battery are affected by the charge and discharge rates.  Its possible that the higher power charge tickles the issue I described previously.  Since the internal resistance of the battery changes slightly every cycle its also possible that it was a one off.   Was that the 1st time you charged the battery?  

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

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