A Novel Dependence-Decoupling Method for Battery Cell Balancing

Existing battery balancing methods compare voltage or state of charge difference between cells during charging and parking to determine whether turning on the balancing circuit. Since these methods require the balancing measurement and control happened at the same stage, the effectiveness of these methods depends on the duration for charging and parking. To eliminate the dependence on operating conditions, this paper presents a novel balancing method to decouple the dependence between the balancing measurement and control by dividing them into two independent stages. The two independent stages real- timely estimate the difference of the state of charges between cells during charging and parking and control balancing at all operating conditions such as charging, parking, and especially driving separately. Our simulation shows that the proposed dependence-decoupling balancing method are very effective for rarely charging and parking applications.