An energy system for providing electrical energy to a device where the energy system includes: a first battery for providing a first electrical power over a first time period; a second battery for providing a second electrical power over a second time period, the second battery being a type different from a type of the first battery, the second power being greater than the first power and the second time period being smaller than the first time period; and a controller for controlling initiation of the first battery and the second battery at predetermined times to satisfy a specific power requirement of the device over a time period including the first and second time periods.