Battery Life
Battery Life In Phone Mode
Battery life tests with the iPhone can be dangerous to your health. At least if you want to test longevity in phone mode. I had just begun to shake the tiredness associated with working into several early mornings testing and playing with the iPhone, when I decided to test the battery in phone mode.
There has been a lot of controversy about battery life in this mode. People have reported anything from 5 to 8 hours. Apple claims 8 hours. Before telling you what I got, let me say something about how the iPhone works in phone mode with all settings at the default level.
- The display is automatically turned off by the proximity sensor when you bring the device to your ear. If you remove the phone from your ear and activate the display in phone mode, the display is automatically turned off in a matter of seconds.
- If you use a wired set of ear-buds with a microphone, the display is automatically turned off after a few seconds. The same is true if you use a Bluetooth headset.
- Edge is disabled during a call; only the carrier name (AT&T in this case) is displayed; no "E" for Edge is displayed.
So, basically, if you're only talking on the phone, most of the battery drain will come from the phone call itself. If you move around a lot, the accelerometer might consume some power and a small amount of battery power will be used by the CPU, supporting chips and memory as the OS does housekeeping, monitoring and other tasks.
Also, if the signal is weak in there area where you are located, the iPhone will raise power to receiving and sending components to optimize your connection. This will drain the battery much faster than in situations where the signal is at maximum levels. And, of course, if you are using Bluetooth to link a headset to your phone, all bets are off, Bluetooth consumes a great deal of any phone's battery power, shortening battery life considerably.
Here is how I set the iPhone during my battery life test.
- Auto adjustment of display brightness turned off and brightness set to mid-level
- Voice simulation using a talk radio station with the iPhone close enough to the radio to provide the other phone, which had its speaker turned on, with easily heard, undistorted sound
- iPhone not moved during the call; the display was turned on (press Home button), every now and then to check the battery meter and to take photos.
- Absolutely no other iPhone functionality was used during the call.
Signal strength was extremely high throughout my tests and the signal was never dropped.
Here's what I wrote immediately after the battery was exhausted and the phone finally stopped running.
"Oh my. The iPhone finally ran out of battery power at around 1:12 am PDT (-8 GMT), after remaining on the test call for over 9 hours and 24 minutes."
These tests cost me a lot of minutes, 564 to be exact. I've still got some rollover minutes, but, though I know it will eat battery like crazy and shorten call longevity, I'm not quite ready to do a Bluetooth battery test in phone mode. Give me a few days more to recover from the last test.
Oh yes, in case any of you doubt the results I obtained, here is photographic proof of my findings. Sorry for the picture quality, but after over 9 hours monitoring the test and at past 1 AM, I was a bit out of it.
With 5% of battery power remaining, has been running over 9 hours.
Just before shutdown.
