Abstract: In order to promote the maintenance efficiency of the storage battery in automatic guided vehicle (AGV), a battery diagnosis system was designed by adopting A/D conversion, ModBus vehicle positioning, network transmission via ZigBee wireless Internet of things and computer programming technologies. The system is composed of a computer, a wireless Internet of things and a mobile data acquisition unit. The system is divided into a data acquisition level, a transmission level and an application level. The data acquisition level is used to extract the real-time voltage of each battery cell in the storage battery group, the transmission level is used to transmit management instructions and data feedback, and the application level is responsible for modular programming with token scheduling algorithm, to realize the online monitoring and remote diagnosis of storage battery of AGV. Five AGVs in the high-bay material warehouse of the Huize Cigarette Factory of HongyunHonghe Tobacco (Group) Limited Corporation were tested, the results showed that the system could online monitor the running state of storage battery in AGV real-timely, locate the fault unit in the battery group accurately with 100% accuracy. This technology provides a support for promoting the monitoring level of power unit in AGV.