Uninterrupted power supply system

The utility model provides an uninterrupted power supply system, include: DC power supply, storage battery, oading equipment, combination switch circuit, battery management system and controlling means, the combination switch circuit with storage battery establish ties the back with DC power supply's output parallel connection, controlling means respectively electric connection in DC power supply's output, and electric connection in the combination switch circuit is with control closed and the disconnection of combination switch circuit are accomplished storage battery charges or discharges the function, battery management system with storage battery is parallelly connected, with the basis each battery cell's state carries out corresponding voltage management among the storage battery, oading equipment with DC power supply's output is connected. Through the utility model discloses, it is in the problem that the floating charge state influences its life -span for a long time to have alleviated the battery.