Anyone figure out what the purpose of the extra Remote Controller Charging Cable is? It doesn't appear to connect to the charger. As far as I can tell one end connects to the battery and the other to the remote controller. So... can you charge the remote controller from the battery???

Yes,  that is what the extra cable is used for.

Except that you shouldn't be charging the battery AND the radio at the same time.

Abe,
The cable is used to charge the controller when you are in the field and the controller is going to run out of power.
You can use the flight battery which is even less than 30% capacity left to charge your controller.
It can also helps the flight battery discharge to capacity learning level, the capacity of the battery will be more accurate.

Ghoonk,
You can charge both when charger is put on the ground.

Oh, great! Thanks!

How do I hook up the flight battery to charge the controller? Do i connect the two-pin end to the battery and the other end to the remote?

Yes,  exactly.
After the connection, power up the battery.

Wow. That's a brilliant feature to have. Thanks for the tip!

DJI-ZT Posted at 2015-1-6 19:17
Abe,
The cable is used to charge the controller when you are in the field and the controller is goin ...

Very cool. And clever. Thanks!

Shouldn't it work the other way around?  My flight battery drains long before my remote controller battery.  Anybody know if there's a way to recharge the flight battery from the Remote Controller?  Especially since backup flight batteries are impossible to get right now.

Mine doesn’t do anything. By power up, you mean hit the battery check.