Component Evaluation and PSpice Modeling for Charge Pump Based Cell Voltage Balancer Development

Batteries are becoming increasingly important in a variety of applications, including electric vehicles and ships as well as load matching in electric grids. Cell voltage balancers are critical to extracting maximal performance out of batteries and also to extending their lifespan. Charge pump balancers can quickly and efficiently shuttle charge across battery cells to equalize voltages. Component selection of MOSFETs, capacitors, and gate drivers is vital in optimizing for efficiency, performance, cost, and volume. This paper presents experimental and PSpice simulation data from several capacitor-based charge pump configurations designed for cell voltage balancing. During testing, our optimized prototype 2S and 4S capacitive-based balancers demonstrated a max pumped current of 6.2 A at 0.4 V cell differential and of 10.4 A at 0.8 V cell differential. Ultimately, these charge pumps can be combined to construct a high-current and multi-level cell voltage balancer efficient across a wide range of voltages.