Heavy military packs could soon get lighter WAKIL KOHSAR/AFP/Getty Images

Bulletproof batteries could soon be used as armour for soldiers. Lumping military kit around on foot is a tiresome job, with batteries accounting for as much as a quarter of the weight they have to carry. But if they doubled up as armour too that could drastically lighten the load.

“The average soldier is carrying roughly twenty pounds (9 Kg) of body armour and eighteen pounds (8 kg) of batteries in the field,” says Gabriel Veith at Oak Ridge National Laboratory in Tennessee. “If we could integrate the two …