摘要 |
A battery system uses passive nonlinear electronic devices, such as zener diodes, respectively connected in parallel to each of the serially connected battery cells, such as lithium ion battery cells, connected in a string, to maintain all of the cells at a balanced state of charge, and will automatically correct any initial imbalance in the states of charge of individual cells. The passive nonlinear devices are preferably matched to equally force each battery cell to have an exponentially rising rate of internal capacity loss as cell voltage increases, while keeping cell voltages and capacities matched. The devices will not accelerate open circuit losses of the cells as the cells become fully discharged as a consequence of conducting low currents compared to the cell charge and discharge currents without generating excessive heat for improved safety.
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