My Gta02s wont charge

Werner Almesberger werner at
Sun Jun 22 23:28:43 CEST 2008

Andy Green wrote:
> You're saying that you don't think we can ever bring the CPU up at all
> if you have a battery in there that is < 2.5V?

I'm not sure. My understanding of the PCF50633 manual says that, if we
enable the charger, we should be fine. My experimental results don't
quite agree with this.

There's one catch: if the battery drops low, the internal protection
circuit turns off power completely. If you tickle it a bit by supplying
external power, it instantly snaps out of this mode and you get battery
power again for a bit.

What I don't know is if any internal processes of the battery (i.e.,
chemical recovery) could cause a transition as well. So far, I haven't
seen this happen, but I didn't do any long-term experiments.

> ~ Or all of this only happens if we disable charging from the previous
> session?

If we disable charging, then - according to my understanding of the
documentation - we're certainly doomed, since there's no way to get
power to Vsys.

- Werner

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