Meet the FatBat 2: a power handle and external battery that lets you handle your smartphone or action camera like a pro. It comes with a mounting system that lets you use your action cam and smartphone together. You can also mount other accessories such as lights and external microphones.
FatBat 2 has a battery that lasts over 10 hours. It is compatible with a variety of action cams. The new FatBat is smaller and lighter than its predecessor. It is expected to ship in July.[Source]