Maybe something like this? https://www.bhphotovideo.com/c/product/1470615-REG/sanho_sahj307g_hyperjuice_usb_c_pd_battery.htmlWe have his-and-hers motorcycle helmets that require a plug-in charger for the wireless Bluetooth com. It is a total pain to babysit charging one for 4 hours, and then waking up in the middle of the night to charge hers up becasue of one packed (large) charger, or a cheap *** motel who only has one electrical outlet in the bathroom (No kidding! Everything else is hardwired into the wall.). Wish the things had interchangeable batteries because the cabling is a mess of down time.
I agree changing batteries must be faster. The USB power brick can run/charge a phone while in use somewhat (probably a tablet as well), but probably can't do much with the camera that way.Bit of a sidebar, but what is the reasoning behind people wanting a USB-C charging port on a camera (e.g. Supposedly the upcoming E-M1 Mark III or whatever.). I don't understand those who'd refuse to buy one if it doesn't have it.
I get it for devices where one cannot change the battery as with cellphones and tablets, but I can swap a dead battery out in a digital camera with a new one far faster than dealing with plugging in a charger to the camera and waiting to resume shooting while it sits charging up.