Modeling, parameterization, and benchmarking of a lithium ion electric bicycle battery

A lithium-ion battery from an electric bicycle conversion kit is tested and modeled using electrochemical impedance spectroscopy, and the hybrid pulse power characterization test (HPPC). Equivalent circuit model parameterizations are obtained from both time and frequency domain fitting and compared. Parameterization methods are described and a novel quadratic programmed-based two stage parameter fitting algorithm is presented to process and generate model parameters. Experimental data is applied to the proposed algorithm to assess fitting performance. The battery model is validated by real-life riding cycles. Additional electric bicycle benchmarking tests are performed to assess real-world battery performance under a variety of riding conditions and at different assistance levels. The brief correlation between tiredness and assistance levels is investigated.