METHODS AND APPARATUS FOR DISCHARGE PROTECTION IN A STORAGE SYSTEM

Methods and systems for discharge protection in a storage system are provided herein. For example, a grid detection circuit configured for discharge protection in an AC battery system includes an input side that is configured to connect between a DC power source and a battery management unit (BMU) of the AC battery system and an output side that is configured to connect between an output side of an inverter and an AC power source, wherein when the AC power source is detected by the grid detection circuit, the grid detection system allows the inverter to maintain a charge at the DC power source and the battery management unit (BMU) to operate within an under-voltage-lockout (UVLO) at or above a first charge threshold, and wherein when the AC power source is not detected by the grid detection circuit, the grid detection system allows the inverter to maintain a charge at the DC power source and the battery management unit (BMU) to operate within an under-voltage-lockout (UVLO) at or above a second charge threshold, and when the AC power source is not detected by the grid detection circuit and a charge of the DC power source falls below the second charge threshold that is different from the first charge threshold, the grid detection system allows the battery management unit (BMU) to enter a sleep mode.