I just bought a Schwinn Izip with the SLA battery on sale at Canadian Tire for $349.95. I'm just looking at batteries and they are more expensive than the whole bike I bought. I love my NiMH batteries in my camera, I have the same set since 2004 and just keep recharging them, they seem to last forever.
If I take lets say 30 D cell NiMH batteries, but do not weld them, they will be press fit together with springs. This may cause corrosion but I will be able to take the batteries out and charge in pairs (4 at a time), and clean the contacts after each use. There may be a gel for the contacts that will stop corrosion also. With 30 D cells I will be at 36 volt, and should be able to avoid draining them deep enough to get into the balance issues. Any thoughts on this?