GS70 Stealth Pro External Battery

I plan on flying across the ocean in the next few weeks and having just gotten my GS70 a little bit ago, I realized I really need a spare battery. Seeing as the laptop is NOT really designed for a second battery for easy swapping, that leaves me to use an external battery source. Now my problem is, trying to find a decent external battery that is ALSO compatible with MSi. That last being the hardest part of all to achieve. I don't need to be able to do heavy gaming during the flight, but...

GS70 Stealth Pro External Battery

GS70 Stealth Pro External Battery