Could you elaborate a bit on why this is? We normally have a very good VZW signal, but Saturday evening we went to a class reunion out in the boonies. I was trying to keep up with the scores on our favorite college football team's game and the signal was nearly nonexistent. The battery was draining so fast that I had to just turn the phone off and check about every 15 minutes, or else I would have drained it in about half an hour.
Going to use an analogy to explain this situation. Will break it down into two parts.
Part 1: The cell phone by itself
Imagine you are a cell phone. You see the cell tower two miles a way. You talk in your normal voice and the tower hears you just fine. As you walk closer you find that you can get down to a whisper and the tower still hears you. As you walk away, say to 20 miles, you have to scream at the top of your lungs for the tower to hear you.
This is what happens with a cellular radio. The amount of power you need to talk is directly proportional to the line of sight distance. You can go from as low as 1/8 watt of power all the way up to one watt of power to talk to the tower. As you add in things that block your line of sight to the tower, this adds to how much power you need to transmit to over come the blockage.
Part 2: The cell phone in a crowd.
You are still the cell phone. You are two miles away and you notice there are 100 people in a circle around this tower. You notice you have to talk slightly louder to get the tower to hear you now. As more people join you, the louder you need to speak for the tower to hear your.
Now the good news on this one you won't get to the full 1 watt of power, even in a very dense crowd, if you are close to the tower. But you will still use more power than if you were alone. In fact before you would go to full power you would probably be more likely not be able to talk to the tower until someone leaves. Towers can only handle so many signals at once.
Conclusion.
With all of this in mind you probably hit three conditions at once. Long distance to the tower, building with a lot of metal studs and a lot of active cell phones directly around you. Odds are you went to full power trying to maintain a connection to the tower. You can probably drain an iPhone in under 3, possibly 2, hours with that condition.
Hopefully that answers your question.
