This is the kind of technology innovation I like to see. "Killer apps" are common as muck these days. Technology like this extends the life of your gadgets (good for people in remote areas) and reduces the amount of batteries being dumped in landfill sites.

This is where Batteriser comes in. It’s essentially a voltage booster that sucks every last drop of useable energy from ostensibly spent batteries. So, instead of using just 20 percent of all the power hidden inside of your Duracells and Energizers, Batteriser makes effective use of the remaining 80 percent.

— Batteriser is a $2.50 gadget that extends disposable battery life by 800 percent
by MacWorld