This sounds like a natural progression of MimoBot line. Let’s hope they can reach their goal:

BatteryBot is the world’s 1st & only character-based rechargeable backup battery for smartphones, tablets & mobile devices, by Mimoco!

Mimoco®, The Art Toy meets Consumer Electronics Design Studio based in Boston, MA (and makers of MIMOBOT® character-based USB flash drives!) is proud to introduce the new MimoPower line of mobile charging accessories.

Compatible with Most 5V Devices powered via USB

• Apple: iPhone, iPad Mini, iPad, iPod…
• Samsung: Galaxy, Note, Nexus…
• others including: HTC Droid, LG Nexus, Motorola Droid Razr, Sony Xperia, Blackberry Z10, Nokia Lumia, Amazon Kindle…
• and many more like: Nintendo DS, Pebble, Google Glass, Dropcam, GoPro, Boombotix, Jawbone, Jawbox, The Pill, TomTom GPS…

Visit their kickstarter for more details and to support the project!