Three hours and 10 minutes, give or take a little, from a completely charged iPhone 4. That’s via Wi-Fi, as compared with a promised 7 hours of voice-only talk time over 3G, and 10 hours of standard data time over Wi-Fi—the difference is attributable to iPhone 4’s camera, mics, speaker, video and audio encoding and decoding capabilities all being used at the same time. Note that we tested two iPhone 4s on this one, seeing average…
