Abstract: Disclosed herein are a vehicle or other system battery with a self-contained backup capability and a method for providing power to a vehicle using the vehicle or other system battery with a self-contained backup capability. In one aspect, the vehicle battery comprises, a main battery portion, a backup battery portion, and a control device for selectively communicating a transfer of energy from the backup battery portion to the main battery portion when a voltage level or other health indicator of the main battery portion is determined to be below a reference voltage threshold, wherein the main battery portion and backup battery portion are each re-chargeable via an alternator of the vehicle when the control device communicates the transfer of energy between the main battery portion and the backup battery portion.