Disclosed herein is a modular energy storage unit comprising one or more power packs that comprise one or more supercapacitors. The one or more power packs may be coupled together in series or parallel and connected with charging hardware. The energy storage unit is associated with an energy control system that manages the charging and discharging of the power packs as the energy storage unit power a device such as an electric vehicle and when the energy storage unit is being charged. In related aspects, the energy storage unit receives charge from solar cells or other alternative energy sources, and charging of the power packs is managed according to a database of information about the individual power packs in the energy storage unit to individually delivery of charge to each power pack to optimize the overall performance of the energy storage unit.