Debalancing protection circuit for a battery pack

摘要

The protective circuit has a monitoring circuit (9) for detecting voltages (U1a-U5a, U1b-U5b, U1c-U5c) applied across individual cells (2) of a cell composite (5) and outputting a signal when the comparison of the voltages with each other exceeds a debalancing limit assigned to the composite. The limit indicates a permissible voltage difference between two selected cells and is defined as a characteristic line based on a state of charge (SOC) of the composite. The limit is variable to change the line based on a correction value that is formed based on an operating variable of the composite. The operating variable is a historical operating variable, which is a load collective formed over the operating time of the cell composite and a temperature collective formed over the operating time of the cell composite.