PURPOSE: To detect a defective battery while sustaining the operation of an uninterruptible power supply and without interrupting power supply to a load even if a defective battery is mixed in serial backup batteries.
CONSTITUTION: When a voltage command selection switch 22 is switched by a battery inspection command, a test voltage slightly higher than a discharge end voltage, set by a test voltage setter 23, is outputted from a charger 3 and since it is lower than the terminal voltage of a serial battery 5, power is fed from the serial battery 5 to a load 6. The voltage of each battery or battery group connected in series is then measured utilizing the discharge current thus detecting a defective battery. Even if the terminal voltage of the serial battery 5 drops abruptly due to a defective battery, power is fed to the load 6 from the charger 3 in place of the serial battery 5 and the load 6 is operated continuously.
YAMAMOTO SHINPEI
TAKIZAWA SHIGERU
