Dear JoeDeath,
I have the same shaver, and I've just had the same problem. I failed to source replacements on the internet so decided to experiment.
At first I wondered about the original cell voltage as both mine were completely dead, zero volts, and would not take a charge. As you say, there is no giveaway data on the casing. The charger puts out 12Vdc, so I thought they might be 3V or 6V cells. Anyway I had lying around a pack of Poundland's finest NiCd 800mAh AA 1.2V rechargeables (branded "OSEL") and, as the Braun warranty had expired, I had nothing to lose so I stuck them in. Guess what - they work.
Since the standard cells do not have pins at both ends they are slightly shorter than the originals and do not fit, so I fashioned a small coil of copper wire for each cell and inserted it at one end to act as a conducting shim. I hooked one end of the wire into the "U" shaped spade terminal to hold it in place. A bit of electrical tape can also be used to hold the cells in place if you wish. The main thing is to ensure the cells are held tightly in contact with the terminals and cannot move about. I Reassembled the shaver, charged it up for a few hours, and voila!
I suspect they do not supply replacement batteries because they would rather you bought a new shaver.
Happy Bodging.
Roger the Bodger, September 2009
