Advanced Battery Management Technologies for Electric Vehicles

6Battery Charging

6.1 Background

Battery charging in electric vehicles (EVs) is similar to refueling a tank in internal combustion engine vehicles (ICEVs). Battery charging involves many issues such as charging scheme, charging power transfer, charging facility, and charging algorithm. Among them, the charging algorithm is the key to battery charging, which has a direct impact on energy usage and the cycle life of battery systems in EVs. This chapter first provides a brief introduction to the charging scheme, charging power transfer, and charging facility, and then there is a detailed discussion of charging algorithms.

Many charging schemes have been developed to recharge battery systems in EVs. They are mainly divided into four categories [1]. The first category is normal charge. It usually takes 5–8 hours to fully charge battery systems. It facilitates load leveling when performing charging overnight in a residential garage or car park without causing extra burden to power systems. It generally adopts a single‐phase AC, 110–240 V, 13–20 A, and 2–4 kW. The second category is opportunity charge. It allows charging of battery systems in a public car park many times whenever possible as long as battery systems are not fully charged, and extends EV driving range without causing significant burden to power systems. It typically uses a three‐phase AC, 110–240 V, 32–80 A, and 8–20 kW. The third category is fast charge. It charges battery systems to 80% of their normal capacity within ...