The TTR's digital controller (the large, finned-aluminum box hung beneath the battery pack) monitors both throttle input and rear-wheel speed, then uses that information to transmit power from the batteries to the motor. Made by DMC (Digital Motor Control) in Germany, this is a beefed-up version of the same highly tunable control unit used on the production Enertia. Manipulating the controller's voltage and current settings, along with other more discreet parameters, creates the "throttle map" that determines the rate at which available torque is metered to the rear tire. The controller is currently air-cooled, but Brammo says it will be liquid-cooled in the next version, since the unit is essentially operating at its thermal limit. A stand-alone, 12-volt electrical system, located under the tailsection, powers the instrument cluster and other conventional electronic components.