Patent ID: 8878489

Claim:
An estimation method for a residual discharging time of batteries, comprising the steps of: A. setting a series of battery-discharge-current intervals for a discharge procedure from a discharge start step to a discharge terminating step and multiple separate battery-discharge equations thereof, with each of the multiple separate battery-discharge equations corresponding to at least one of the series of battery-discharge-current intervals, and further setting a discharge time of each of the series of battery-discharge-current intervals at zero; B. detecting a discharge current, a discharge time and a discharge voltage of the batteries; C. judging whether the discharge current exceeds all of the series of battery-discharge-current intervals, and terminating if the discharge current exceeds all of the series of battery-discharge-current intervals; D. selecting one of the multiple separate battery-discharge equations corresponding to the at least one of the series of battery-discharge-current intervals according to the detected discharge current; E. calculating a residual discharging time of the batteries; F. accumulating and recording the discharge time of the at least one of the series of battery-discharge-current intervals corresponding to the selected separate battery-discharge equation; G. judging whether the discharge voltage is lower than a predetermined value, and returning to the step B if the discharge voltage is higher than the predetermined value; H. calculating an estimation error of the residual discharging time when the discharge voltage is lower than the predetermined value; I. judging whether the estimation error is greater than a predetermined error value, and terminating if the estimation error is lower than the predetermined error value; and J. adjusting parameters of the selected separate battery-discharge equation if the estimation error is greater than the predetermined error value.