Abstract:

 A three-stage optimization method was proposed for constant current constant voltage (CCCV) charging to improve the charging speed and the charging efficiency of on-board lithium batteries. The threestage optimization method was modified based on the battery charging model of the Next Generation Automotive Cooperation Program (PNGV). The polarization voltage and the open circuit voltage were used to correct the control object in the constant current and constant voltage process, so that the current and voltage change in real time with the actual state of charge of the battery. An implementation scheme was designed on an embedded chip STM32F103 platform. Experiments with 4 different charging methods were performed. The results show that compared with the other three charging methods, the three-stage optimization method can increase the charging efficiency to 94.25%, and the charging time can reach 900 s, and the battery capacity attenuation value is reduced by 45% compared with the un-optimized. Therefore, the method has a good fast charging effect.

Key words: lithium battery for vehicle ,  battery charging model , constant current constant voltage (CCCV) charging , open circuit voltage , chip STM32