A low cost lithium-ion battery tester with a zero voltage discharge capability

A battery tester is an important equipment for battery manufacturers to understand several characteristics of a lithium-ion battery including dc and/or over-discharge properties. This paper proposes a low cost battery tester that can discharge the battery to zero voltage under a minimized current ripple to evaluate the characteristics of a lithium-ion battery. The circuit of the proposed tester consists of two basic bidirectional buck converters with no additional switch or auxiliary circuitry structure. In addition, to ensure the minimization of the current ripple components, a link voltage variation scheme is adapted. Due to these properties, the proposed circuit enables to provide a low cost and a good DC characteristics with a low current ripple. The performance of the proposed battery tester is verified by several simulation and experimental results with a lithium-ion battery as a load.