System and methods for determining battery system energy capability in a vehicle are presented. A voltage offset of a battery system may be determined based on comparison of an open circuit voltage of the battery system and a measured voltage. An estimated remaining pack energy may be determined based, at least in part, on the voltage offset. Similarly, an estimated total pack energy may be determined based, at least in part, on the voltage offset. An energy capability of the battery system may be determined based on the estimated remaining pack energy and the estimated total pack energy.