Getting our batteries to charge

Harald Welte laforge at
Tue Apr 3 10:33:31 CEST 2007

On Tue, Apr 03, 2007 at 04:21:14AM -0400, Richard A. Smith wrote:
> So far we have been running out Bv3's off of a lab power supply.  I've 
> been looking at bug 212 and the charging problem claims to have been 
> fixed in 1511.
> I put u-boot-gta01bv3-r4_0_0_1569.bin in one of our phones this weekend 
> and left it plugged in 

'plugged in' into what?  A self-powered or root USB hub? 

Or the almost-beyond-hope not-according-to-our-spec power supply that
was sent together with the Bv3?

In the former case, it should trickle charge with 100mA until 3.3V
battery voltage is reached, then power up the CPU (not the LCM),
enumerate on USB and charge with 500mA thereafter.

In the latter case (wall outlet charger):  Please just don't use that
device.  Safely put it away where it cannot cause any further harm
and/or confusion.  It will never be used to charge more than 100mA.
Even that should charge the battery (and has shown to charge mine here),
but maybe something in your phone has not yet been switched off, which
draws an average of >= 100mA and thus there is no charging happening.

> for over 24 hours but it still won't turn on via 
> the battery.

I have to say I'm utterly surprised by this, given the fact that I'm
constantly experimenting with half a dozen of phones of various hardware
revisions, I have not seen this problem happening even once.

If you have the time (and equipment), please try the following:

1) try to measure the current to/from the battery using a multimeter

make sure you get the polarity right so you can tell if there's actually
current into the battery, or from it to the device.

2) try to measure the battery voltage 
2a) of the idle battery
2b) of the battery while charging begins
2c) of the battery after some time (>= one hour) of charging

Thanks for your assistance.

- Harald Welte <laforge at>         
Software for the world's first truly open Free Software mobile phone

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