Flow-by Lead-acid - Improving the Performance Standard for EV Battery Systems

The Advanced Battery Business Unit (ABBU) of Johnson Controls, Incorporated (JCI) is working on a contract sponsored by the United States Department of Energy (DOE) for the design and development of an advanced lead-acid battery system for electric delivery vehicles. Significant improvements in specific energy on a cell basis during the last year have positioned this technology within 6% of the contract goal of 56 Wh/kg. Currently, the majority of engineering efforts are directed towards improving the cycle life of this high performance battery. This goal is proving to be the most challenging due to the transient power nature of the SFUDS testing profile which provides a more accurate simulation of an EV duty cycle than the previously utilized constant current test regime. These efforts will culminate in the fabrication of a 180 volt, 39 kWh battery system which satisfies the performance, life, and cost goals for safe and efficient electric van propulsion.