The main research goals of lithium battery charging strategies include four aspects: minimizing charging time, maximizing efficiency, maximizing capacity, and maximizing cycle life. However, there is a competitive relationship between different targets, shortening the charging time requires increasing the current rate, and a large rate current will also increase the polarization voltage, thereby reducing the charging efficiency. Therefore, how to balance the relationship between different goals based on battery characteristics has become the focus of current research on fast charging technology. At present, there are three safe fast-charging strategies. Fast charging is essential for batteries especially for golf cart battery.
1. Safe charging strategy based on SOC and SOH estimation. The strategy adopts real-time monitoring of battery voltage and current to estimate battery SOC and SOH. Therefore, the current rate and the upper limit voltage of charging are adjusted according to the state of the battery. The strategy is easy to control and implement while improving the charging speed and safety. Lithium battery safety is a must.
2. On the premise of a balanced consideration of the aging loss and charging time of lithium batteries, a multi-stage constant current charging strategy is proposed based on the electric-thermal-aging multi-parameter coupling model, which can accurately characterize the physical and chemical reaction characteristics of the battery itself.
3. A fast charging method that takes into account the battery hysteresis effect is adopted. The main idea of this method is to establish the functional relationship between the battery open-circuit voltage OCV and the state of charge SOC, to evaluate the energy required for charging. Greenbatt 48V, 72V EV battery support fast charging and no harm to battery performance and cycle life.
