DARPA style RC car... sorta

Heya
I'm turning an RC car into an autonomous vehicle, and I have a leetle question. I'm planning to go cheap and use the BOE bot that I already have to be my controller.
My question is whether or not it would be safe/possible to hook up my RC car's speed controller to the BOE bot. It has PWM inputs, so it hook up fine, no hacking there. The worry that I have is that the RC radio doesn't have it's own battery, it just uses the one from the speed control. Would there be any risk hooking up the speed controller to the BOE bot? Programming comes second, it's the mechanical I gotta figure out first...