10,000 mAh Portable Charger
Speaking of charging the HTC One M8, there's so many portable powerbanks or chargers that it's hard to get a good one. We like the brand TYLT, but Anker has some quality stuff too. With a 2,600 mAh battery in the HTC One M8, this 10,000 mAh charger will fully power your device about 3 times when you truly need power. Anker's 10k pack has two ports to charge multiple devices too.
Buy on Amazon for $25.99