Methods and systems are provided for controlling a power transfer rate in to and/or out of a vehicle energy storage device to affect a current state of charge of the energy storage device. The vehicle may be on a mission comprising a plurality of future power transfer opportunities. In one example, the method comprises adjusting the power transfer rate based on an estimated duration of a future power transfer opportunity. Further, the method may include, if the estimated duration of the future power transfer opportunity is different from a predetermined threshold, changing the power transfer rate at the future power transfer opportunity. The method allows the operating life of the energy storage device to be extended.