Yeah I am an Amondotech fan, "titanium pow power" is so ridiculous it is funny. :-)

I did more research on our batteries after those posts.

The cells in the HCH-I are slightly larger than a D-Cell, and are custom manufactured by Panasonic. I found a pic on howthingswork.com wrt hybrids. Don't know about the HCH-II, but probably similar.

They are also appear to be rated at many more charge/discharge cycles than consumer NiMH's (1000 typically). I couldn't find anything on why however.

I heard here that they generate about 100 amps at full assist, and take about 50 amps at full charge. Doubt those little spot-welded tabs on the Amondotech batteries would take that. The picure I saw of the HCH batteries showed very large connectors at the + end of each battery.

The idea of a 50% increase in the mAh capacity of my pack for $1k was very attractive however. :-)