An apparatus includes a power converter, one or more power source terminal configured to connect to a power source, and one or more load terminal. The apparatus further includes two or more energy storage terminals configured to connect to two or more electrical energy storage devices. Two or more protection circuits, included in the apparatus, one for each of the protection circuits, is electrically connected between the respective energy storage terminal and the power converter. The two or more protection circuits are configured to disconnect the respective terminal from the power converter following a failure of the respective one of the electrical energy storage devices.