Mint Energy – Portable Batteries recharged by shaking

Since the batteries themselves can be recharged, without the need for a larger charger device, it means you can top the batteries up whilst you're on the move. However, due to the small size of the coil, its likely that you'll be generating very little energy. Therefore its likely that you'll get no useful amount of energy out from the batteries. I would prefer to have a larger charging device that could be powered by foot movement, which would generate more energy but without being so exhausting.

Unfortunately no technical specifications or pricing information is available. I get the impression that the Mint Battery is just a concept rather than a product.

Source: Mint Pass