Design and Implementation of a Residual Capacity Estimator for Lead-Acid Batteries

This paper proposes a residual capacity estimator with higher accuracy for lead-acid batteries. The calculation method is using different discharge capacity rate of a battery in different discharge current to calculate state of charge. Therefore, curve fitting state of charge estimation has the ability of revising value of state of charge with the changing of lode, and this improves Coulomb state of charge estimation. Thus more reliable state of charge estimation value can be obtained when battery discharge in heavy loads and the proposed method is more suitable for different discharge lode. The control core of state of charge estimation of the plan is the digital signal processor (TMS320F240). The DSP gets the battery of discharge current and voltage signal, in order to estimate state of charge and discharge end respectively.