You don't mention the gear ratio. I've run the numbers on various gearboxes using 10 beefy CP2400SCR cells, and the currents I get are much too high for any 1700mAh KAN cells:

4.4:1 ratio = ~45 Amps
5:1 ratio = ~35 Amps

These kinds of currents might be okay on Sanyo CP1700 cells in short bursts, but the KAN cells I'm thinking of can't do more than 25 Amps. Not all 1700mAh cells are created equal. Did NESail tell you to use those specific cells?

Overloading cells causes their voltage to drop drastically without draining much capacity (as long as you don't overload them for long periods of time).

Swap that pack out for a pack of Sanyo HR4/5FAUP 1950mAh NiMH cells. These cells are the same size/weight as the KANs, but have a lot more punch.