Dogcom is a relatively young brand of powerful batteries for FPV drones. The UCELL series aims to provide quality batteries at an affordable price. The Dogcom UCELL 850mAh 4S is a Lipo battery with XT30 connector suitable for 2.5" Cinewhoopy or 3-4" racing and freestyle drones.
Before using, please read The Principles of Safe Use of Lipo Batteries.