   Cell phones, GPRS, IMAP IDLE and power consumption
  After a bit of a debacle last month, I was left without a cell phone. I decided to get a new one, and since I had a bit of money I decided to go for some more bells and whistles. I found one with a 3.6 V 950 mAh battery, with a stated stand-by time of 385 (or 365, depending on the network) hours. To obtain real-world figures, I usually divide the stated maximum by two, which for this phone would make for about a week of stand-by. However, something is eating its battery faster - I get more like 40 hours of stand-by - and I'm not sure what.I've turned off bluetooth, automatic network searching, animated backgrounds and other similar power sucking features, and set the display brightness to the lowest possible value. I've also made sure that all data that needs to be accessed more often than once a day or so resides in phone memory, not on the memory card. That leaves one thing: push email from my GMail account.Push email is implemented through IMAP IDLE, whereby the client keeps a connection to the server open, sending keepalive packets every 15 minutes and otherwise just waiting for the server to notify it of incoming email. I figured that this wouldn't noticably affect power consumption, since there very rarely is any activity. It would seem, however, that I was wrong.Does keeping a GPRS connection alive really require that much power, even though nothing is sent? Is there anywhere I can learn more about the properties of GPRS connections (in a slightly less dry format than a 2000 page specification,) and more specifically regarding idle activity and power consumption? Is it possible that there is some other detail I've missed that could cause the battery drainage?   