Hello, my iphone6 has been using for over 2 years and the battery health is around 80% only. the battery is only marginally sufficient to support Mavic to fly for 3 batteries' flights.

I found a battery case (called "Smart Battery Case") in Apple Store but not sure if it can be used at the Mavic Pro remote control.
this case will keep the two sides of iPhone basically the same thickness because the battery is placed at the middle of the case. thus, I think it can be put into the remote control.
it provides a lightning slot outside the case and claims to be working for data transfer and charging as well.  
the core question: is it ok when the iPhone is being charged by the battery case, and is connected with the Mavic remote control at the same time?
anyone has the idea on it?

Iphone6 Smart Battery Case

see below for the product details in Apple Store:
http://www.apple.com/shop/produc ... 6fh%3D458b%252B45bf

I've found that the Smart Case will work with the Mavic Pro RC remote, but it does not provide power.  The battery on your phone will drain to 0% while using it with the RC remote, while the case battery remains at 100%.  It seems that the case is only capable of very slowly recharging the phone's battery - much slower than you drain it using the RC remote.

It's a shame, because I'm in the same situation with my iPhone 6.