The structure principle and technology demand of Ag-Zn battery for UUVs are studied,and the mechanism and damage of battery overcharge and over discharge are analyzed. According to the potential change concept of Ag-Zn Battery,the charge-discharge regularity is explained,and the usage scheme,related technology and successful experience in preventing overcharge and over discharge are stated. To solve the practical problems of Ag-Zn battery,an improvement program of low current charge-discharge and low temperature storage is proposed, which has been proved to be effective in promoting the performance and quality life of battery.