EZ-Start 2, complete system with controller, drive unit, wiring harness The Traxxas EZ-Start system brings the power, convenience and safety of push-button electric starting to the TRX 2.5, 2.5R, or 3.3 Racing Engines. Simply plug in the hand-held control unit, push the button, and the EZ-Start system automatically heats the glow plug and the lightweight, compact on-board drive spins the engine. Traxxas' exclusive Smart Start technology monitors critical starting functions, automatically sensing and diagnosing potential problems for trouble-free engine starting every time. The EZ-Start requires a fully-charged, 7.2-volt, 6-cell battery pack and a charger (not included). A single charge should provide a full day of starting.