As I am planning for a trip to NZ and going for milkyway and southern lights time lapse, I need a good source of power supply to my A7r mk1. I got a grip but mostly not enough for that long duration and I couldn't afford to off/on it to change battery.

Recently, I saw a video at YouTube about using dummy + power bank for those long duration time lapse. Therefore, I ordered 2 of it (dummy battery) and forget about the W series batteries as Sony also going into Z series. On top of that, I still can use the power bank in the future.

While taking out the grip, I am wondering. Since I can use a dummy battery + power bank, why Sony (or other) don't develop a grip that has a build-in or removable power bank? Maybe the capacity could be over 10k mAh easily, save the process of making more batteries. It's a win-win situation as can have less waste product too. Really hopes to see such feature in the future camera.