A typical infantry platoon needs to carry more than 150 pounds of batteries if it is going on a five-day mission. The batteries power devices like night vision devices, laser range finders, radios, GPS, laptops, etc.

The U.S. Army is working on replacing the batteries with fuel cells made from ethanol.

[Read and Listen](http://www.npr.org/templates/story/story.php?storyId=5386468) (NPR)