**warning** this may be obvious to some hardcore iPhone people. ) Since my first iPhone (3GS), I've had a theory that keeping you brightness on high all day will draw more battery than any other feature (equalizer enabled, Bluetooth, LTE, wifi enabled when not using wifi, and anything else you can think of). Obviously if you turn on airplane mode it lasts forever. Now, I don't know it this is true, it's just my speculation, but it would be awesome to finally get the opinions of some crazy hardcore iphone guys because everyone I've shared this opinion with just says "maybe, hey, do you know when breaking bad starts?" So what do you guys think? If you have two phones and turn brightness up all the way on one and down on the other, the one with the lower setting will last significantly longer. Thanks.