I would agree Nat, normally you could get almost continual use with a 50% over voltage but

there are other factors like the near stall factor of the motors when trying to push another bot.

Motors are going to run hot when over the specified voltage then you add the load it's kind

of asking for trouble-I still include a slip clutch in the design but even that has limited

tolerance when you push too hard so I will up the spec of my motors where I can to be

more compatible with voltage input.