Fault tolerable Li-ion battery stack

Li-ion batteries are embedded in numerous systems, such as EV, airplane, ships, and IDC etc. Therefore, Li-ion battery stacks are critical to the safety and reliability for these applied systems. In this paper, a fault tolerable circuit topology and fault isolation scheme for Li-ion battery stacks is proposed. Since one MOSFET is connected in series to each cell, the stack is tolerable to one cell fault, which is either short-circuit or open-circuit. Once one cell fails, the faulted cell will be isolated and the battery stack is able to continue to operate. The detecting of cell state is achieved by sensing the drain-source voltage of each MOSFET. Finally, a prototype is built to verify the design of the fault tolerable Li-ion battery stack.