Adaptive gain sliding mode observer for state of charge estimation based on combined battery equivalent circuit model.

Highlights: [•] State equations are derived from the combined battery equivalent circuit model. [•] An adaptive gain sliding mode observer for state of charge estimation is purposed. [•] The new observer minimises the chattering and improves the estimation accuracy. [•] The experiments of a lithium-ion battery verify the effectiveness of the observer. [ABSTRACT FROM AUTHOR]