Abstract: Taking lead-acid battery (VRLA) as the research object,the charging protection system based on single-chip microcomputer was designed for the cause of fire and explosion of the battery. Fire reason of battery during charging was analyzed.The software and hardware were introduced.The single-chip system based on Proteus 7 was simulated. Simulation results showed that, the charging protection system based on singlechip can achieve the automatic power off and alarm function when no less than 2 main runaway happen. The protection system can protect the charging process from the fire, and can provide reference for study on battery charging protection system.

Key words: electric bicycle fire, lead-acid battery, thermal runaway;hydrogen evolution explosion, charging protection device