PowerBook battery fun

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As mentioned before, I recently bought a Powerbook G3 for about 20 bucks on eBay, its a “Bronze Keyboard” model, also known as “Lombard”. It appeared, that it was nearly in perfect working order, after I plugged in a hard disk with already installed OS X 10.3.9 Panther system on it. Every second boot the screen stays black – which is a bit weird, I have no explanation for that. Unlike the Pismo, this model do have an earlier version of open firmware, that does not react to a long pressed power button to force shut down, so you have to plug it of and remove the battery – which, on these machines is done simply by pulling a small lever at the front of the palm rest. This ingenious design allows for quick removal and exchange of the battery, but there’s more to it. In fact this devices housings have two of these bays, and in its standard configuration a battery sits in the left bay, while on the right side the DVD drive is located, which is also removable, even while the computer is running. This right bay can then take another battery, easily doubling the time of power autonomous operation. The battery is smaller than the DVD drive, so a spring-actuated hatch is covering the gap between the housing and the battery when the DVD drive is removed. I am simply loving it. This affection to mechanical design may have to do with my primary job as a toolmaker…

Being my first mac, the Pismo is still special to me and I try to keep it in working order. Now, the batteries gave me a hard time recently. A few years ago these could still be obtained at reasonably costs, but now they are nearly impossible to get, at least for an acceptable price. That made me try the procedure described here, to rebuild my battery pack with new cells.
The cells were about 50,- Euro and it appeared that opening the old battery housing was the hardest step in this procedure, connecting the new cells was not a big thing. At first the battery was charging normally, but the computer went into sleep or even shut down when the charge still showed about 45%. When plugged in afterwards, it showed up as completely discharged. This happened for about 4 or 5 times, then the behaviour changed. The charging cycle was interrupted after about 10%, showing only the plug sign inside the battery icon, not the charging flash. Unplugging and reconnecting the machine and the battery several times brought back the flashed icon eventually, the battery got another 10% of charge and then stopped again. Doing this repeatedly would eventually end up in a fully charged battery, but of course, this is a pain.

I did some research on the web and finally I found an Apple tool called “Battery Reset 2.0”. The drawback: it does not run on OS X and it does not work with the Pismo. It requires a OS 8.1 to OS 9 installation and works on Wallstreet and Lombard models only. Wallstreet machines had completely different batteries, with other connectors and 14.4 volts, while the Lombard is compatible with the Pismo (10.8 volts). So my recent acquisition came in handy. Applying the tool on a battery plugged into the Lombard caused it to appear completely empty, and the first charging cycle acted as a calibration for the battery PMU. Afterwards charging was possible without stops and the fully charged battery lasts about 3 1/2 hours now.