Electric vehicles that mix with normal traffic must provide bursts of high torque as they accelerate from standstill to operating speed. Battery systems that are sized for sustained driving experience excessive drain during each acceleration from rest. A system providing a separate small battery for acceleration and the means to isolate the main battery from brief peak current demands is presented in this paper along with the benefits in weight, cost, and range that result. Operation of the General Electric Delta research vehicle with and without the dual battery system demonstrated the distinct advantages of the hybrid battery system.