23 Apr
2014
23 Apr
'14
7:48 p.m.
Tim,
Following your advice, I disassembled a battery, and directly connected the
output of a 3.6v motorola charger to gnd and positive side of the charging
pcb (of course the lithium cell is completely disconnected). See pictures
below, gnd is the middle pad whereas the positive pad is on the left. When
doing so be careful not to heat or pierce the lithium battery, and
afterwards put some tape to ensure electrical isolation:
https://drive.google.com/file/d/0ByHQWL5Q6bSwOHVPNlV5T2ZyZndLZmwtMF9JQ2V0eH…
https://drive.google.com/file/d/0ByHQWL5Q6bSwTGNfeUFOVFM5cldPNFZ3djMyMmlSNV…
https://drive.google.com/file/d/0ByHQWL5Q6bSwUm9XUnBOcU5SRFg4T3VpNEFZOUFHaU…
The result appears to work although strangely sometimes after unplugging
the charger for some time and replugging it the microcontroller on the pcb
will not wake up. However it does immediately wake up if I measure the
current between the + and - output with a basic multimeter, but with the
black probe on the + and the red probe on the - (other way does not work).
There's probably something I'm missing here, but it's not that big a deal.
Maybe this is caused by a quirk in the microcontroller, as I've tried the
same procedure on a new compatible battery (branded "OTB", see
http://pmcdn.priceminister.com/photo/926610349.jpg) and it doesn't have
this problem, the microcontroller wakes up immediately and powers the
phone. The voltage might be a bit too high, but the phone seems to work
fine (firmware reports a full battery - also it gets slightly hotter).
On Wed, Apr 23, 2014 at 3:05 PM, Christophe Devine <
devinechristophe(a)gmail.com> wrote:
Tim,
Following your advice, I disassembled a battery, and directly connected
the output of a 3.6v motorola charger to gnd and positive side of the
charging pcb (of course the lithium cell is completely disconnected). See
pictures below, gnd is the middle pad whereas the positive pad is on the
left. When doing so be careful not to heat or pierce the lithium battery,
and afterwards put some tape to ensure electrical isolation.
The result appears to work although strangely sometimes after unplugging
the charger for some time and replugging it the microcontroller on the pcb
will not wake up. However it does immediately wake up if I measure the
current between the + and - output with a basic multimeter, but with the
black probe on the + and the red probe on the - (other way does not work).
There's probably something I'm missing here, but it's not that big a deal.
Maybe this is caused by a quirk in the microcontroller, as I've tried the
same procedure on a new compatible battery (branded "OTB", see
http://pmcdn.priceminister.com/photo/926610349.jpg) and it doesn't have
this problem, the microcontroller wakes up immediately and powers the
phone. The voltage might be a bit too high, but the phone seems to work
fine (firmware reports a full battery).
Christophe
On Thu, Apr 10, 2014 at 8:44 PM, Tim Ehlers <osmocom(a)ehlers.info> wrote:
On Thu, 10 Apr 2014, Max.Suraev(a)fairwaves.co
wrote:
I modified the mobile battery, removing the battery itself, and
ohh, this is no "advanced" modification. I just read on the battery, that
it outputs 3.7V, then I found for an ACDC-adapter, outputing 3.3V DC (this
is enough, but the phone tells you that the battery is nearly empty if you
boot the original firmware; but we use osmocom :).
I openened the white plastic cover (or more correct, opened the sticker
around the battery), removed the Li-ION battery from the little electronic
parts and soldered the DC-adapter there instead.
Cheers
Tim
replacing
it with a
3.7V AC-Adapter, so that I don't need the charging.
Interesting - can you describe those modifications in more details?
Which adapter have you used? How did you connect it exactly? Some pics?