https://detail.tmall.com/item.htm?spm=a230r.1.14.1.44a45e18zlD5A2&id=544047948526&ns=1&abbucket=8
I got these kind of dummy battery (connected to a USB socket, and power the camera with a power bank). Can get it from Taobao (directly, or via EZ Buy). Its normally a lot cheaper to get the same...