I'm wondering if it might be possible to Charge your batteries on the fly.
I know it's possible to connect your spark to a power bank to charge the battery connected to it, but is it possible to fly with one battery and charge the 2. at the same time?

Does anyone have an idea how this could be done?


Also why does the charging hub have 2 USB connections? When I first bought it, I thought the hub would double as a power band

Isn't one of the USBs for charging the RC

You can charge it with an AC-Powerbank.. but I would rather buy more batteries for the price for an AC-Powerbank.
http://forum.dji.com/thread-106030-1-1.html

The Micro USB port at the side is for firmware upgrading at this moment. Thus literally, it is not recommended to charge the battery with charger hub via power bank.

Thanks
@djiThor, is it not possible to charge the spark directly? Could it be problematic?
I've read people do it before.