Multi-stage constant current charging strategy considering SOC intervals and voltage thresholds

Abstract

Conventional multi-stage constant current charging strategies often use higher multiples of current to charge the battery in pursuit of shorter charging times. However, this leads to an increase in battery temperature, while shortening the charging time. This in turn affects the safety of the charging process. Furthermore, the higher charging currents are not ideal for shortening the charging time in the later stages of charging. To solve the aforementioned problems, in this study, a multi-stage constant current charging strategy is presented. This strategy can shorten the battery charging time by using the increase in battery temperature during the charging process as a constraint, using a genetic algorithm to calculate the charging current value, and investigating the phased approach to charging. Finally, the charging strategy is experimentally validated at different ambient temperatures and different initial SOCs. The experimental results show that the charging strategy proposed in this paper not only reduces the amount of calculations, but also reduces the temperature rise by up to 46.4% and charging time by up to 4.2% under different operating conditions.