Remote controller battery boost

[TerryJ]

If you use the usb port on the bottom of your remote to connect your device. You can connect a battery booster/charger to the micro usb port on the side of the remote controller. It will greatly increase your battery life and number of flights. I use a 5500 mah booster and it allows me to go thru 4 full mavic batteries and its still at 100% battery!!

 

[Thastinger]

that is sweet but is it practical for most peeps? How may mother ship batteries would you need to drain before the controller became the weakest link to flight time?