Sizing the battery power for PHEVs based on battery efficiency, cost and operational cost savings

The incremental cost for increasing the power of Li-ion batteries for plug-in hybrid-electric vehicles (PHEVs) is moderate. Hence, the reduction of fuel consumption by using battery power at high vehicle speeds rather than engine power results in high net present value for the total cost of the battery and future fuel savings. The variation of designed efficiency at rated power is also evaluated to examine the cost for the thermal management system and improved life and cold temperature performance. Two types of PHEVs and two lithium-ion battery chemistries of batteries are considered in this study.