I don't think he's just lucky. What I've experienced so far is that using some communication methods is draining the battery. Summary of my observations:
1. Everything off - 1% up to 2% battery drain per hour. (weak signal)
2. Wi-Fi ON - 2-3% / h
3. Cellular data ON - 6-8% / h (!!!!!) (weak signal but still H+)
4. Location - Can't really say, but around 2-5% / h
5. Everything ON - 10-13% / h (while not in wifi range - around 8-10% within range)
6. Everything ON except Cellular data - 4-7% / h
Please try it and report how it looks for you. For me it's cellular data killing my battery. I need to switch it on only when it's needed. This way I'm satisfied of battery, while I'm NOT using the phone. Because my next observation is, when screen is ON - it drains battery faster than on W8.1 (mixing it with cellular data usage and I got -45-55% / h).
There's one more thing to mention. Battery is old and exhausted so it will not perform as a new one, but I would be glad to hear how it looks with other people's phones.
Data carrier is always know draining fast, but it happens on all phones of all brands, 3g or 4g, since years. The most drain activity remains obviously calling