The present disclosure includes devices, systems, and methods for managing vehicle functions according to power demand by vehicle subsystems. Example methods include receiving available power data indicating available vehicle battery power, the vehicle having vehicle subsystems. Methods include receiving demand data indicating a battery power demand by the vehicle subsystems that perform vehicle functions. Methods include receiving modification data associated with modifying the vehicle functions. Methods include determining, at a first time, based on the demand data and the available power data, that the power demand exceeds the available power. Methods include selecting, in response to that determining, target vehicle functions among the vehicle functions. Methods include selecting, based at least in part on the modification data, modifications for the target vehicle functions. Methods include initiating the modifications to the target vehicle functions.