A Raytheon team has developed vehicle armor that doubles as a battery – a breakthrough that could power electronics, reduce engine run times and lessen the military’s demand for costly, dangerous fuel convoys.

The armor, described in a September 2015 patent, works by layering bullet-resistant electrical conductors such as high-hardened steel with sturdy insulators such as ceramics. The result: Power goes through it. Bullets do not.

“My department manager, when he saw it, said, ‘Wow. Batteries that stop bullets,’” said Gary Wahlquist, one of the engineers named in the patent.

The batteries store the energy that vehicles generate while in motion. When the vehicles are stopped, the crew can switch to battery power, rather than having to run the engine just to power their on-board electronics.