One of the biggest things I’m concerned with on my smart phone is battery life. What good is a wireless phone if it always needs to be plugged in? With some of my older iPhones (iPhone 2G, 3G), it was a major issue. But since I’ve gotten my iPhone 4, it’s never really been a problem.

I’ve had Android and Blackberries for work phones in the past, and I can honestly say the iPhone 4 is the best when it comes to battery life. Well it looks like my experience are in line with most everybody else’s, as cnet test results confirm that the iPhone is top dog…

The iPhone 4 from AT&T was able to playback video for 9.9 hours straight, while the Verizon version topped it with 10.3 hours. The best Android competitor was the Google Nexus S, made by Samsung, which checked in at 8.1 hours. Coming in dead last is the HTC MyTouch 4G, the one you see in the T-mobile commercials bashing the iPhone 4 for lack of wireless video chat, at 6.6 hours of video playback.

The audio playback tests were even more enlightening. The Verizon iPhone 4 topped out at 67 hours of audio playback, while the HTC MyTouch 4G topped Android phones with 21 hours. It was also interesting to see that the AT&T iPhone, while still well above the Android competition, came in at 40 hours of audio playback.

What’s with the 27 hour difference? Unlike the video tests, the audio playback trials were done with airplane mode off, so it’s likely they were in an area with poor AT&T coverage. When a phone constantly searches for service, the battery will drain quicker due to the strain.

Has anyone else seen similar playback times or have their own iPhone 4 battery life opinions? Tell us below!