Body Armor with Batteries Scientific American

Patent No. 7,805,767 - Youd never catch Iron Man lugging around seven kinds of batteries.

But thats exactly what U.S. Army squad leaders are required to do on 72-hour missions. The batteries, which can weigh a total of 16 pounds, are used to power radios, GPS systems and night-vision goggles.

Source:
http://www.scientificamerican.com/article.cfm?id=body-armor-with-batteries&WT.mc_id=SA_CAT_physics_20101224