Embodiments of the present disclosure relate to a heating, ventilating, air conditioning, and refrigeration (HVAC&R) system that includes a variable speed drive (VSD) configured to supply power to a motor configured to drive a compressor of the HVAC&R system, a rectifier of the VSD configured to receive alternating current (AC) power from an AC power source and convert the AC power to direct current (DC) power, a DC bus of the VSD electrically coupled to the rectifier, an inverter of the VSD electrically coupled to the DC bus, where the inverter is configured to convert the DC power to output AC power, the output AC power has a variable voltage and a variable frequency, and the output AC power is directed to the motor, and a battery electrically coupled to the DC bus, where the battery is configured to provide auxiliary DC power to the VSD.