In all fairness, there are two hamsters that work in shifts. In power mode they both work at the same time. That is how it gets you up the hills. But the hamsters have to be replaced after three hills.
When I was volunteering at the loacl 'bicycle kitchen' a retired Chrysler exec donated several of these early ebikes. Their original SLA batteries were long gone. We replaced those with Ping branded Li-ion battery packs that were custom made to fit these bikes. With just a few other minor updates they were ready to go.
Apparently the original design relied on the high internal resistance of the SLA batteries to limit power to the motor. With the much lower resistance Li-ion batteries these bikes went literally like bats out of h###. I put a Wattsup meter on one. The motor would pull up to 1KW at full throttle.
Mechanically, they were nothing special, esp with their stamped sheet metal frame, but boy would they go with new batteries