PowerBook 140 shorted battery - possible rebuild?

[mitchW]

I just acquired a PB 140 in a very good condition. It needed some stuff to be done (recap the LCD screen, lubricate head bearing in the HDD as the HD wasn't recognised, etc.). The funny thing is, I got it from Germany, the keyboard is US and the system is Japanese (System J-6.0.7.1).

However, before I even turned it on, I checked the battery and it was at 0V and dead shorted.

I tried charging it with an 5V PSU and it drew 20 amps!

So, I opened the pack and checked the cells. Most of them were a bit oxidised, and almost all of them showed dead short when tested with ohm meter.

Anyone tried rebuilding the battery? The cells have 1.6 cm in diameter and 4.9 cm in lenght. They look non-standard. Anyone has a source for these batteries?

Should I just use 5 or 10 NiCd 1.2V eneloops or something and wire them in series?

 

[rsolberg]

The Japanese system is kind of a unique situation with these first generation Powerbooks. The computers shipped with System 7.0.1, but Apple didn't have Kanji text implemented in System 7 in time for the computers to ship in Japan. A special build of System 6 (6.0.7.1 KanjiTalk) was produced as a workaround for Japanese configurations. In addition to this, the 140 shipped with 2MB of RAM, which was considered barely adequate for System 7 by many users at the time. System 7.0.1 was the official minimum operating system for this model and ordinary System 6 builds/installers would not run on the machine. Some intrepid users got their hands on the special version of 6.0.7 for Japan and installed it or parts of it in order to get a working System 6 on this unsupported machine.

In regards to the battery, NiMH cells with solder tabs would be my inclination. Eneloop or other low self discharge cells are a good idea By your measurements, AA cells should work as replacements at 1.5cm x 4.9cm. I'd use the same number of cells as the original and you'll probably end up with somewhat higher capacity. Most low self discharge AA cells are nominally 2000mAh, so two series sets of five in parallel should give you 6v 4000mAh.