The system has two parts: a remote controller unit for the pilot and a receiver mounted on the drone. Both of them need 5-13v. In my case I'm using an UBEC connected to the flight battery for the receiver and a simple 2s lipo for the rc.|
The only thing I don't like is the fact that the transmission from the receiver to the A7 is an infrared signal. That means, in very sunny days it could be weak, but i will see this in summer. Maybe it's not really a problem, the distance between the iR-Diode and the A7 is just 5 cm in my case, it depends on your method to mount it.
With this you are able to switch all relevant values for the exposure. I was totally p*** off when I was realizing that the iR-port on the Zenmuse is only able to do the shuttering command, nothing more! This is a shame for DJI... they sell it as a PRO-system :-(
Intelli-g (https://intelli-g.com) is also selling a solution, it works with WiFi. It's more expensive, but you don't have the (possible) iR problem.