A hybrid battery power module composed of lead acid and LiFePO4 batteries for BLDC motor drive is proposed in this study. The lead acid batteries are used as the basic power source and directly connected to the motor drive without any power conversion losses. In addition, to enhance the instant power supply capability to the motor drive, the LiFePO4 batteries are integrated into the proposed hybrid battery power module. A two-phase interleaved dc converter is adopted to control the power flow among the LiFePO4 batteries, lead acid batteries and the motor drive. The common power requirement from the motor drive is designed to be totally provided by the lead acid batteries. Once the power demand became higher than the common level, the additional part would be instantly provided by the LiFePO4 batteries through the interleaved dc converter. The life of the lead acid batteries can therefore be enhanced by the high charging/discharging capability of the integrated LiFePO4 batteries. A prototype with 500W rated power is constructed. Corresponding experiments are carried out to verify the validity and performance of the proposed hybrid battery power module.