Qtek 8500 as a Music Player: The Battery Life
August 4th, 2006 Jason Dunn
Testing battery life is notoriously difficult to do with any degree of accuracy: there are software programs that help test battery life, but using software is a synthetic test that doesn’t always accurately reflect real-world scenarios. The only way to get true, real-life battery tests is to duplicate the exact scenario in which you want to evaluate the battery performance. In this case, I wanted to test how long the Qtek 8500’s battery would last when playing music. Here’s how I did it.
The photo above shows my testing interface: the Qtek 8500 was loaded up with 128 kbps WMA files, all 260 of them on a Sandisk 1 GB microSD card, shuffled and repeated using Windows Media Player 10 Mobile. The master phone audio level was at 100%, and the Windows Media Player 10 Mobile volume was set at 80%. With the Qtek 8500 headphones, I felt this was a reasonable maximum volume - 100% volume was, to my ears, simply too loud. The volume slider on the headphones themselves was at maximum volume. I then took a Plantronics microphone and placed the end against the headphones. This was then connected to my laptop, which was running Sound Forge, recording the input from the microphone. This allowed me to record the output of the headphones and easily see in Sound Forge when the music playback stopped.
For the purposes of this test, I left the phone’s radio active, meaning it could still accept calls. No one would want to turn off the ability to accept phone calls while listening to music (unless you were on a plane). What I did turn off, however, was my Exchange ActiveSync. Since the frequency of ActiveSync differs so much from one person to the next, I wanted to eliminate it as a factor in these tests.
So how long did the Qtek 8500 last in this scenario? An impressive 10 hours and 11 minutes. I have to admit, that’s longer than I thought - the phone has a 750 mAH battery, which is quite small for a Windows Mobile device. The 10 hours battery life means you could use the Qtek 8500 for music five hours a day and still have 50% of your battery life left for primary tasks such as phone calls.
It’s worth noting that in every battery measurement I’ve seen, the device manufacturers always use MP3 files rather than WMA. I’ve read that WMA files require more CPU cycles to decode than MP3 files, meaning it’s a bigger drain on battery life. That will be one of my next tests: repeating this procedure with 128 kbps MP3 files instead and see if it increases the playback time.