There really is nothing special about coin batteries as a retrofit into Amigas. The original was a rechargable Nicad. Provided you match the voltage (and the polarity, of course), the capacity (usually measured in mA/hours) can be just about anything. I use cordless phone batteries fron Radio Shack. I splice on longer leads so they can be tie-wrapped far away from the motherboard (and easier to inspect and replace

). If they do leak in the future, the board won't be damaged.