The utility model discloses a battery monitoring devices, it includes that the battery observes and controls host computer, battery collection module and a plurality of monomer and holds the battery test module, battery collection module includes main control unit, busbar voltage sampling circuit, floating charge electric current sampling circuit, fills a discharge current sampling circuit and a RS485 communication circuit, the monomer holds the battery test module and includes battery end voltage detection circuit, holds internal resistance of cell detection circuitry, battery temperature detection circuitry and hold electromotive force of a cell detection circuitry. Through using this monitoring devices, can monitor the parameter among the multiple battery system, can do benefit to the staff like this and go on reliably and effectual maintenance to battery system to guarantee that battery system is stable and move safely. The utility model discloses a but the monitoring devices wide application is in the battery field.