FPVGuy & Bo Lorentzen interview Energen Sales Director Victor @ 2017 InterDrone on Youtube
2017 September
Portable recharger for your drone batteries, price works out to about 2.5 Phantom batteries, and manage to charge about 5 batteries, so basically you get bit more flying on site for less money than buying 5 batteries. See more detail on youtube, link: https://www.youtube.com/watch?v=loCXbc6J2eM&t=5s