A method of calculating the SOC of power batteries based on fuzzy neural network

A new estimate method is proposed to describe the state of the batteries in hybrid-electric-vehicle (HEV) in this paper. The batteries are Ni-MH batteries that have a normal capacity of about 6.5 Ah, and are used in a kind of HEV. The HEV application is a very harsh environment with high charge or discharge rates and very dynamic rate profiles. The normal definition method state of charge(SOC) that work well in begin portable electronic applications may not work well in the HEV application. The normal definition of SOC cannot contain both the static and the dynamic message of the batteries in the only word. In the new definition method, the SOC is calculated applying Fuzzy Neural Network. This SOC indicates not only the static capacity message of the batteries, but also the dynamic state of charge while charging or discharging.