Method for estimating residual energy of battery

No load calculation step of calculating the energy of the battery no-load; Step calculated estimated for calculating the estimated energy expected to reflect the energy consumption due to internal resistance and polarization on the calculated no-load energy; And calculating a correction value proportional to the difference between the estimated terminal voltage and the current measured terminal voltage and the residual calculation step for calculating a residual energy by reflecting a correction value in the estimation of energy; the estimated remaining battery energy comprises a is introduced.