To provide an SOC estimator which can enhance the accuracy in estimation of SOC by executing SOC estimation, taking the general properties of a battery where the responsiveness in a low frequency region is high into consideration, and an electric vehicle mounting it.
The SOC estimator is equipped with a monitoring means which monitors the charge/discharge frequency of the battery and the cycle of the charge/discharge, a battery SOC estimating means which estimates the above battery SOC in operation cycles geared to the charge/discharge frequency of the battery, and an operation cycle changing means which controls the above SOC estimating means so that it may make the operation cycle of SOC shorter the shorter the cycle of the charge/discharge of the battery is.
Kazuaki Takami
Hiroshi Tokunaga
Shiro Fujitani
Kiyoshi Kuruma
Kazuyuki Tomita
Eiji Fujiwara