Hmmmm....well maybe my watch is not working properly....as with 2 - 7.2 volt 3000 mah NIMH batteries.....in my back yard....with my driving style....I can run for about 30 minutes. Now....that is not wide open mind you....it's just goofing off trying this....trying that....enjoying it for the same reasons that you described.

And yes....it's wise to let the motors cool between runs.

Good Luck!