I just got the HTC one m8 a few days ago. The battery is awful, I tested the exact same games and videos on both my HTC and iPhone 5 of 2 years ago and the iPhone beat it.. I have airplane mode and power saver mode enabled yet can't play pixel dungeon for 10 minutes without the battery dropping 4-5 ℅ . I've read reviews saying the one m8's battery was great but I think mine is defective, should I return it?