Power Management Systems and Methods

Various embodiments of the teachings herein include a system comprising: a local supply of renewable power; a storage device with a discharge characteristic; a switch for electrically connecting the storage device to the local supply; and a system controller. The system controller may be configured to: receive from the local supply a signal indicative of available power; read from a memory a time history of past activations of the storage device; estimate a future demand of power based on the time history; estimate a charge of the storage device based on the future demand of power and the discharge characteristic; compare the charge to the future demand of power; and if the charge is larger than the future demand of power by a predetermined margin, electrically connect the local supply of renewable power to the storage device by closing the switch.