Problem with battery charging

[Harald Welte]

On Wed, Mar 21, 2007 at 02:08:04PM +0100, Nils Faerber wrote:
> Hi!
> I just recognised a little issue with battery charging...
> 
> Yesterday I put the NEO on the charger and let it boot. It booted up
> fine and started charging the battery.

please don't use the battery charger, as it will only charge with 100mA,
which will take at least 12 hours to fill the battery, if the device is
switched off.  

if you keep the device running, it will consume more than 100mA, and
thus actually run empty - just a bit slower than it would without the
charger.

With devices up to GTA01Bv3 and the current charger we basically have no
way of using a non-usb-host for charging without violating the USB spec.

So now we have the choice between USB incompliant 500mA charging (which
might in some really bad cases cause damage to the 'usb host' it is
attached to.

Thus, we'd rather done it the safe way:  Only use 500mA after the USB
host has granted us permission to do so.

I know that it's almost industry practise to violate this part of the
spec.  However, OpenMoko wants to set a good example and adhere to
standards :)

GTA01Bv4 and the new charger hardware contain circuit changes to address
this problem in a usb spec compliant way.

you can manually override the charging mode via sysfs or in u-boot, if
you really want to use the charger for 500mA charging. see the kernel
and u-boot pages in the wiki.

cheers,
-- 
- Harald Welte <laforge at openmoko.org>          	        http://openmoko.org/
============================================================================
Software for the world's first truly open Free Software mobile phone