Rapid charging strategy in the constant voltage mode for a high power Li-Ion battery

In this paper, a fast charging strategy of a Li-Ion battery charger operating in constant voltage (CV) mode is investigated. Typically, in CV mode, high potential is induced across the battery. This increases battery losses and charging time. In addition, a high power stacking battery has an unknown parasitic parameter due to series or parallel connections between batteries. This gives rise to unstable conditions for the battery charger. The relationship between these is analyzed for a robust charging control strategy. The proposed rapid charging control strategy is to use a multi stage current with respect to the battery´s internal impedance. Experimental results based on a 40Ah Li-ion battery charger are used to validate and demonstrate the performance of the proposed control scheme. Based on the proposed control scheme, the charging time was reduced when compared with conventional CV mode control.