Failed battery hack- analysis?

cenobyte at cenobyte at
Mon Oct 10 23:46:48 EDT 2011

 On Tue, 11 Oct 2011 00:22:20 -0300, Werner Almesberger wrote:
> cenobyte at wrote:
>> My guess was
>> that I used a bad wire set? or that I should not have had both
>> colors of wire connected.
> Hence my suggestion to measure ;-) There's nothing inherently
> wrong with trying to use a different battery, so you should be
> able to find out why it didn't work.
> In theory, a battery could refuse to deliver more than some
> minimum current before receiving an "unlock" sequence from the
> host, but I haven't heard of this sort of contraption in
> mobile phone batteries.
> Some batteries do have a cut-off state when the charge is too
> low, though. E.g., the battery of the Openmoko GTA02 had such
> a circuit. This is to protect the battery from "deep"
> discharges. In the cut-off state no significant current is
> allowed out of the battery, but it can still be charged. In
> the case of the GTA02 battery, a few seconds of charging make
> the protection circuit exit the cut-off state.
 So you mean to say that headphone wire is a legitimate electrical 
 connector? Or should I run out to radio shack and get some 'real' wire? 
 Does it matter that I touched both color wires of each one to the 
 terminals? and should I have used electrical tape instead of scotch 
 tape? I will try again after my current battery gives out, so far 5.5 h 
 going strong even though Jlime says 0% lol. BTW the reading on the 
 battery is 3.9-4V and it is a motorola bq50.

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