Charge/discharge characteristics of a backup power supply system using nickel metal hydride batteries

We developed an outdoor backup power supply system that employs nickel metal hydride batteries, which have high capacity for backup use, and provides a backup time of 15 hours at 20degC under 200-VA output power. We performed a thermal design of the power supply system and achieved a 0-40degC operating temperature range at 200-VA output. Consequently, the system is a promising outdoor power supply.