State of charge estimator for NiMH batteries

A state of charge estimator for Nickel-Metal Hydride batteries, suitable for hybrid vehicles automotive applications, is proposed. The estimator is based on a statespace dynamic model of the battery which is obtained by modeling the kinetic of reactions and the diffusion phenomena. State of charge is estimated by computing the dynamic behavior of the Ni(OH)/sub 2/ concentrations in the active nickel-hydroxide film and using measurements of current and voltage. The estimator is tested off-line on experimental data and performs good results.