A system includes an ultra-capacitor and battery system comprising a battery, an ultra-capacitor, a DC-DC converter, a first temperature sensor to sense a battery temperature, a second temperature sensor to sense an ultra-capacitor temperature and a third temperature sensor to sense a DC-DC converter temperature. An auto stop/start module is configured to selectively stop and restart an engine of a vehicle while an ignition system is ON based on operating parameters. A temperature sensing module communicates with the auto stop/start module and is configured to determine differences between temperatures sensed by the first sensor, the second sensor and the third sensor and to selectively disable the auto stop/start module based on the differences.
