According to the difficulty of the maintenance of the battery

a design method which adopts bus float is presented. A kind of on-line montoring sensor of batteries is developed. The voltage

temperature and internal resistance in each unit of the battery are digitized in order to realize real time on-line measurement and timely find the failure battery unit. The structural design of the monitoring sensor’s principle and hardware system design are provided. Comparing with the centralized monitoring system which uses the analog signal isolation

this design has better precision and reliability

safety and stability. It has the advantage of low cost

small size

and has good prospect of engineering application.