Presented here is an electrical system for a vehicle having an electrical load. The electrical system includes a primary energy source, a rechargeable redundant energy source coupled to the primary energy source via a first switch, a second switch, a third switch, a fourth switch, and a control unit. The fourth switch is coupled between the electrical load and the second switch, and is coupled between the electrical load and the third switch. The control unit operates the first switch to facilitate charging of the rechargeable redundant energy source with the primary energy source, operates the second switch and the third switch in concert to selectively provide operating power from either the primary energy source or the rechargeable redundant energy source to the fourth switch, and operates the fourth switch to provide the operating power to the electrical load.