VERY promising update/review of a US AT&T HTC One over at Engadget regarding battery life:
While the 2,300mAh battery in the global model lasted six and a half hours in our usual rundown test (video looping, brightness fixed at 50 percent, etc.), our AT&T review unit lasted an average of seven hours and 29 minutes, besting the global model by about an hour. As for real-world use, the AT&T model carried on like a champ, lasting through a full day of maps us, podcasts, photo-taking, Facebook, Twitter, app downloads and speed tests. Even after eight hours, we still had about half a charge left.
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Woah, unfortunately, The Verge counters Engadget's positive battery test:
Finally, the AT&T HTC One offers the same 2,300mAh non-removable battery as the international model. David found the international One to have just average battery life in our review it can be made to last the entire day if you are careful, but it's not a long distance runner by any means. There's always concern that speedier data networks will have a negative impact on battery life, but in my tests and usage on the AT&T One, nothing really changed. In daily usage on LTE, the One would last about 12 hours before tapping out enough to go from 7AM to 7PM, but not into the evening hours. On our standard Verge battery rundown test, the LTE One managed 4 hours and 41 minutes, just about the same as the international model.
When I did some heavy lifting on the device, including watching a movie streamed to the 1080p display (The Expendables 2, if you must know, which looked and sounded amazing on the One), playing Asphalt 7 for 30 minutes, and placing a couple of phone calls, I saw my battery meter plummet 61 percent. Needless to say, the One didn't exhibit astounding battery life in any of these situations, but it mustered a merely average performance. That's half of a win, since you have access to faster data speeds with the LTE model, but it's not something I would get too excited about. Unless Mophie or another company comes out with a case with a built-in battery, power users will want to tote around an external USB battery to make sure they can get through the day.
Sigh... I'm a skeptic of any positive battery reviews given HTC's history, but I sure hope Engadget is more on the money than The Verge.