Razer Kishi V2 on Android

Ok, first off, I just got the Razer Kishi V2 controller for my Android phone. My problem is, my phone battery will not charge while I'm playing my game. Game is Diablo Immortals. The controller is great nothing wrong with it. My phone just won't charge. It's charging before I start the game, but with game started, no juice going to phone battery.