US Patent 11502520 Battery protection circuit with isolation device failure detection

A battery module includes a first load terminal, a second load terminal, a first charger terminal, a charger enable terminal, and a battery having a first battery terminal coupled to the first load terminal and a second terminal coupled to the second load terminal. A first isolation device is coupled between the first load terminal and the first charger terminal and has an enable terminal coupled to the charger enable terminal. A first protection circuit includes a second isolation device coupled between the second battery terminal and the second load terminal and a first sensing circuit configured to enable the second isolation device responsive to detecting a failure of the first isolation device.