A variable drive system, to drive an accessory drive of a machine may include a first variable pulley to be mechanically coupled to the accessory drive and an engine output of an engine. The variable drive system may also include a second variable pulley to be mechanically coupled to a flywheel. The variable drive system may include a drive element to rotate, according to a clutch system, about the first variable pulley and the second variable pulley to at least one of: drive the second variable pulley to charge the flywheel with kinetic energy or drive the first variable pulley via kinetic energy from the flywheel.