Reviving an A1175 Battery for a MacBookPro A1260
Just
took my MacBookPro A1260 (early 2008, 2x2.4 T8300/4GB DDR2/200GB/OSX 10.5.8
upgraded to 10.6.8 Snow Leopard} out of storage. It did not Boot at first with
the battery showing no charge [no LEDs lighting up] but booted after SMC reset
[battery out, magsafe PS out, press PWR button for 10", replug PS, let go
PWR button]. Problem is that you need to do this every time you power up, as
SMC data is not backed up unless main battery.
Only 2GB RAM seen at first, but 4GB showed after cleaning the
RAM SIMM contacts with 90% alcohol
Taking the battery, I unglued the bottom Aluminum plate [the one
with LEDs holes and a battery test button] with a wooden spatula; under that
plate, there is an AL shield locked into the base box [plastic sides with an Al
bottom box engraved with 'Apple, A1175, etc.] by 3 tangs on each side. I remove
the shield: it now shows 2 rows of 3 Batteries, each battery with 2 poles
towards the PCB with its 5 LEDs. In each row, the 3 batteries are in series; I
measured 3.5V for each battery for a total of 10.5V. Looking towards the LEDs,
RHS pole of the 3-battery series is [+], with LHS [-] for a total of 10.5V. I
soldered wires to '+' and '-', then charged the stack at constant current 0.2A
until the stack reached 11.5V. The test LEDs now shine when the battery test
button is pressed. I continued charging to about 12.5V i.e. until 4 'test' LEDs
shining I then removed the wires, plugged the A1175 back into A1260; the A1175
is now recognized with only 170cycles, and charge well in the laptop until 5
LEDs shine. I have now run the A1260 for 1 hour on the A1175, and it is still
at 50% charge.
I do not understand why the A1175 would not show/charge in the
A1260 even though there was still enough voltage [10.5V] in the A1175 battery! Seems
that force charging the A1175 to 12V somehow triggered the finicky Apple
battery circuit to recognize the battery again!
MacBook Pro