Optimal Lightweighting in Battery Electric Vehicles

This paper presents an analytic solution to find the optimal amount of lightweighting in a battery electric vehicle (BEV). The additional cost of lightweighting is traded off against the cost savings due to the smaller battery and motor required at constant performance and range. Current technology cost estimates indicate that for a medium sized BEV, optimal glider mass reduction is on the order of 450 kg in 2012 leading to estimated manufacturing cost reductions of 4.9%. Declining powertrain costs are expected to reduce the importance of lightweighting in minimizing BEV cost in the future, and rising electricity costs to increase the gap between the optimal solutions based on minimizing manufacturing versus total costs. The results are strongly dependent on the future development of lightweighting, battery, and electricity costs. The sensitivity of the optimal mass reduction to these critical parameters has been evaluated, and is shown to increase over time.