iPhone battery life seems to reflect how good your cell phone reception is

I've just realised something quite interesting based on my usage of the iPhone 3GS. It would seem to me that the battery life of the iPhone is affected greatly by the cell phone coverage of your telco.

Recently, I happened to be working at home for the day and I realised that my iPhone battery life only dropped by about 1-2% for the entire day (I was lucky not to get any phone calls during that time). This is not the case when I have to travel to and fro to my official workplace (a drop of 10% or more).

The only difference? I am getting a consistent 4 to 5 bar signal strength at home, while the signal strength is quite low at my workplace. My guess? The iPhone is consistently trying to get a better signal if your signal strength goes below a certain number.

Therefore, if your iPhone seems to be draining more power than usual, check your cell signal strength. It may be the cause of your trouble.