It's rechargable (with a non-contact recharger too, which is pretty cool) - but after two years the battery is no long holding its charge for more than a day. So I figured I'd look up instructions for how to replace the battery. I've taken apart computers plenty of times, how hard can it be?
So I found them, and it all seemed pretty easy. Until I hit the bit where I'd need to desolder bits of the various internal connections, and then resolder them again.
Oh well, new toothbrush for me.
Original post on Dreamwidth - there are comments there.