About 1,5 years ago, I ordered new batteries from a german company, http://www.newtec.de
(I'm in Sweden, so not too far).
Those batteries where 3400mAh, a little bit too fat, so the lid of the battery compartment looks a bit swollen. But they have been working great. They are pretty expensive though, almost double the price of the 2200.
Tomorrow morning, I'm picking up my second trilobite (used) for my basement, and I am pretty sure the batteries will need replacement, so I'm considering the 2200mAh ones for the new one.