New XO 1.5 firmware with MPPT. Please test!

Samuel Greenfeld greenfeld at
Thu Apr 7 15:43:19 EDT 2011

Is there any expected impact to battery health or life from using a MPPT
(maximum power point tracking) charging technique?

How does this behave when it encounters an external charger which may be
inflexible in terms of voltage or current generated?

On Thu, Apr 7, 2011 at 2:59 PM, Richard A. Smith <richard at> wrote:

> On 04/05/2011 12:47 PM, Richard A. Smith wrote:
> Latest version.
> This one really fixes the keyboard problem.  This is what I hope to be
> the final test release.
> In addition to the normal does this work for you. I need one specific test.
> Please flash then boot and stop at openfirmware.  Then run
> 'watch-battery'. Remove external power and  allow you battery to
> discharge to 60% or more. ie (<= 60%).
> Then re-plug up external power and watch what the battery current does.
>  It should pretty quickly go up to around 1A or more.  If it does not
> then please connect up a serial terminal with logging enabled. ( you
> will have to power cycle or reboot to get ofw serial) Remove external
> power and then rather than 'watch-battery' run 'watch-mppt' and then
> replug up power. Let it run for perhaps a minute or so and then send me
> the serial log.
> Thanks
> --
> Richard A. Smith  <richard at>
> One Laptop per Child
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