The invention discloses a UPS uninterrupted power supply comprising a static switch controller, a static output device, an intelligent charger, a battery package, an inverter, a transformer, a filter and a central controller. The output end of the static switch controller is connected to the static output device; the intelligent charger, the battery package, the inverter and the transformer are connected sequentially, the inverter is connected to the central controller, the central controller is connected to the static switch controller; the filter is connected to the static switch controller, and the intelligent charger comprises a voltage step-down regulating unit and a charging unit connected to the output of the voltage step-down regulating unit; the charging unit comprises an output unit, a charging control unit connected to the output unit electrically, a recognition and judgment unit and a switch control unit and controls the charging mode of the charging control unit according to the switch instruction output by the recognition and judgment unit. By the aid of the UPS uninterrupted power supply, the battery can be protected.