Japanese mobile provider NTT Docomo has created a prototype battery that can fully recharge in 10 minutes. NTT displayed the new battery and charger at CEATEC in Tokyo and Engadget was there to report all of the details.

The current prototype on hand was an external lithium-ion battery sleeve that attaches to the back of a phone. The unit was only functional with NEC’s Medias Android smartphone, a Japanese exclusive. Despite the restrictions, the promise of a 10 minute battery recharge has us intrigued.

NTT is able to accomplish such a feat by pumping a lot more juice through the charger into the battery at once. The demonstration showed an amp meter connected to a standard charger as well as one connected to the prototype device. The standard AC adapter pushed .55 amps while the pre-production model boasted 5.86 amps. That’s more than 10.5 times the power being pushed to the battery.

The tech blog says that the model being shown is likely an early prototype and could use some refinements in terms of aesthetics. Additionally NTT had no idea when the unit could move into production and find its way into consumer’s hands, other than saying it would be available “as soon as possible.”

Last month we reported on a jelly-based lithium battery developed by Leeds researchers that could make batteries of the future safer, cheaper, smaller and more powerful. The technology could lead to thinner and lighter notebook computers and more efficient batteries for electric cars and even smartphones.