Amazon.com : Synergy Digital Camera Battery, Works with Panasonic Lumix DC- GH5 Digital Camera, (Li-Ion, 7.4V, 2100 mAh) Ultra Hi-Capacity, Compatible with Panasonic DMW-BLF19 Battery : Electronics
PANASONIC - Battery for GH3/GH4/GH5 - PhotoCineShop | PhotoCineShop - Professional photo and camera equipment
Panasonic GH Series Dummy Battery to 3.5/1.35mm DC Male Cable | Tilta