Module bypass switch for balancing battery pack system modules with bypass current monitoring

摘要

A battery pack system module may include a module bypass switch for allowing charge current to bypass the battery pack system module. The module bypass switch may be activated to divert charging current from the battery pack system module to other battery pack system modules. The charging current may be diverted to bring other battery pack system modules into balance with the battery pack system module. That is, to bring the state of charge of all battery pack system modules into coarse balance. When the module bypass switch is activated, charging current through the module bypass switch may be monitored by a current sensing device such as a current sensing resistor. A microprocessor may receive information about the bypass current level and use the information to determine when to de-activate the module bypass switch. Sensing current through a module bypass switch allows more accurate and quicker inter-module balancing.

主权项

1. An apparatus, comprising:
a first battery pack system module, comprising:
a battery cell coupled between a first terminal and a second terminal;a charge switch coupled in series with the battery cell and the first terminal for interrupting charging of the battery cell;a discharge switch coupled in series with the charge switch and the first terminal for interrupting discharging of the battery cell;a module bypass switch for shorting the first terminal and the second terminal; anda current measurement device coupled between the module bypass switch and at least one of the first terminal and the second terminal.