Abstract
In the development process of electric vehicles, the design of battery systems has long been the most challenging problem due to high energy density and high power density requirements. To date, the problem has been alleviated in hybrid electric vehicles because the employment of internal combustion engines replenishes the energy deficiency of batteries available in today's market. However, the advent of lithium ion chemistry may circumvent the difficulties in design of battery systems for electric vehicles. The safety issues of lithium ion chemistry still concern the public in the past few years due to reported accidents either in the lab or on the road. In this paper, a fault-tolerant battery system consisting of small-format cylindrical cells based upon lithium iron phosphates chemistry is investigated with design details and experimental verifications.