New battery semi-charged but not charging, is protection-circuit broken?

Michael Shiloh michael at
Mon Sep 1 20:08:38 CEST 2008

ankostis wrote:
> On Mon, Sep 1, 2008 at 7:14 PM, Michael Shiloh <michael at> wrote:
>> ankostis wrote:
>>> On Mon, Sep 1, 2008 at 6:28 AM, Michael Shiloh <michael at> wrote:
>>>> Did you update u-boot and kernel? There was a bug awhile back causing
>>>> USB insertions to be only partially recognized.
>>> I have not updated UBoot and i cannot do it anymore since the battery
>>> has fallen significantly making it impossible to enter into USB ACM.
>>> I've used kernel from 2008.8 and FSO (2 days ago), nothing too recently.
>>> I thinki i've seen the bug you mention,
>>> when it requires to insert the USB twice in order to enter 'Charging" status.
>>> But yet, no real current flows into the battery and the battery's
>>> reported capacity remains 0.
>>> Yesterday, the current_now started to show some non-zero values, but
>>> judging from the voltage_now,
>>> the battery did not actually charge.
>>> Michael, I would really like to know if there is any possibility of
>>> reviving the battery or if i should definitely contact the reseller
>>> for a new one,
>>> since i live in a different country from the reseller it and it will
>>> take some time to receive a new battery.
>> If you're feeling adventurous, try to revive the battery using Joerg's
>> unofficial instructions [1], then update u-boot and kernel, then see if
>> charging works better.
>> If you're not feeling adventurous, ask your reseller for a new battery,
>> and if it works, then return the old one as faulty.
>> Michael
>> [1]
> I've tried this already since the current voltage has fallen below the
> booting threshold,
> by supplying extra current from a separate supplier directly to the
> battery receptors.
> Yet i think Michael, that we are not dealing with a dead battery that
> needs reviving,
> but with a broken protection circuit that does not accept the charging current.
> If i could suggest a solution that would be first to deeply-discharge
> the battery
> in order to reset the protection-cpu, and then start charging it.
> Is this a viable solution?

Interesting theory. I don't know how the protection circuit works, and 
whether deeply-discharging will reset it.

You might post this question on the kernel list - the people who would 
know this should all be there.


More information about the support mailing list