I made sure the temperature sensor on
the circuit board and the cell to which it was affixed with heat sink
compound had good thermal contact. Using new heat sink
compound insures this. Then
I put the top of the case on.
Fitting everything together was a little tricky. I was quite
careful not to short any of the cells out.
used electrical tape to hold the two
halves of the case together as a temporary measure. I checked
little green lights on the side, and they indicated that the cells were
discharged. I put the battery in a Pismo powerbook and it
charged. I was able to use this battery for three hours and
minutes on the first discharge. The battery monitor only
estimated two hours though. The second or third discharge cycle,
I left it running with the screen
off most of the time, the hard drive was running the whole time, and I
got nearly seven hours before it automatically went to sleep.
This time, the battery monitor estimated six or seven hours.
I believe that you may be able to reset the
defaults in the battery by booting into open firmware. (Hold
command and O F keys simultaneously while booting.) Then you
issue the commands:
The last command causes your powerbook to reboot. I
these steps yet myself, but it might be a good idea.
After the tests with the battery were successful, I used super glue and
a vise to reseal the battery.
After the first success, I proceeded to the
next battery. I was surprised to find it was packed
than the first one. I kind of think it was a Lombard battery
instead of a Pismo battery, but I don't know. In this battery
circuit board was at the end of the battery. It proved much
difficult to re-assemble because there was very little extra room
inside the case with this way of packing things.
Here are some photos of that pack. Much more care was needed to
make sure that no extra room was taken with the new cells than was used
with the old ones.
Some photos of the process are shown
There is a cable that needs to connected
from the back circuit board to the front one.
I tested the battery after mostly
The silicone grease is needed because
there is very poor thermal contact without it.
Other Notes of Interest
I wanted to do something similar with my early Powerbook G3 Series
(Wallstreet) batteries, but I haven't found a good solution yet because
the 17670 cells are quite expensive and hard to find. There are
twelve of them in those packs. If you have a source that would
provide a dozen new cells for less than $50, I would like to hear of
it. The 18650 cells might work electrically, but they won't fit
A tip from Dieder Bylsma:
"A little tip I found useful for rebuilding the batteries is that you
really need a battery shell that is easy to open. After going through
quite a few shells, I've found that the ones that are easiest to open
are the ones with the *large* serial numbers and barcodes on the bottom
of the battery. Maybe this might be worth mentioning in your site? The
other ones are a pain to open without completely destroying them in the
Two Years After Doing this Battery Replacement
It has been about two years since I replaced the cells in two Pismo
battery packs. These batteries did not last as long as they
should have. One pack is completely dead now, and the other only
lasts about 30 minutes. I suspect that there is something that
needs to be reset when the cells are replaced, but I'm not sure.
If you have information relating to this, I would appreciate
hearing from you.
Other Information on Replacing LiOn Cells
A Good General Article on Replacing LiOn Cells