A method for testing a capacity of a drive rescue battery includes opening a first switching device and second switching device to disconnect a LCL filter from AC mains and form a test load for testing the capacity of the drive rescue battery while disconnecting one of the LCL filter capacitors associated with a third phase from the test load, the test load including a series connection from one of the downstream LCL filter inductors and the LCL filter capacitors associated with the first phase to one of the LCL filter capacitors and the downstream LCL filter inductors associated with the second phase; and determining at least one of a voltage or a current of the drive rescue battery resulting from the test load.