Plan V lets you charge your phone using a 9-volt battery

Smartphones are more powerful than ever, but they still have an annoying tendency to run out of juice just when you need them most. The Kickstarter-backed Plan V could get you out of this, as it’s a small and light keyring-based device that can be used to charge your smartphone from a 9-volt battery.
Likened by its Sydney-based creator Flintu to a car jumper cable for phones, the Plan V isn’t a typical battery charger like the LithiumCard, as it contains no power of its own. Rather, it’s a very small adapter that enables you to plug your phone or similar device into a 9-volt battery that you supply.
The idea is, if your phone dies or gets too low on juice, you whip out the Plan V and attach it to a 9-volt battery, thus getting you around four hours additional talk time on a Galaxy S5 (as an example).