Does iOS 5 or the iPhone 4S have battery problems? We take a look (with video.)

Does the iPhone 4S have a bum battery? Not according to our tests.

Apple iPhone owners have been complaining about shorter battery life on their new iPhone 4S devices, which may actually be a problem with how the new iOS 5 uses GPS to . Apple is apparently .

When we , we found it to last longer than the previous model: 7 hours, 33 minutes for the CDMA device as compared to the iPhone 4's 6 hours, 17 minutes. To look closer, though, we decided to do a head-to-head test.

So we did an experiment. We took a Verizon iPhone 4 running iOS 4, an AT&T iPhone 4 running iOS 5, and a Sprint iPhone 4S. We set them all up with no accounts pushing, Bluetooth off and location services on, and the screen on maximum brightness. The Verizon and Sprint phones had cellular on and Wi-Fi off; the AT&T phone (which had lost its provisioning) had Wi-Fi on and cellular off.

This isn't a perfect test. We weren't testing standby battery life with the screen off. Obviously, our phones were connecting to different networks, and they're of slightly different ages so the batteries would have different levels of charge remaining. But if iOS 5 or the iPhone 4S had a severe battery life problem, it probably would have shown up.

We didn't see a big difference between the three phones. The AT&T iPhone 4 died first after six hours, 55 minutes. The iPhone 4S lasted another 32 minutes, and the Verizon iPhone 4 died two minutes later.

Considering our older iPhone 4 running iOS 4 lasted the longest of the bunch, it looks like iOS 5 may indeed be causing a hit on the battery. The iPhone 4S's larger, newer battery only just matched the older phone, and an iPhone 4 running iOS 5 died the quickest.

The difference, at least in our test, isn't the dramatic horror that some people are reporting on message boards. That doesn't mean users aren't having problems. If the bug is related to time zones, for instance, our phones may just not be triggering the conditions necessary to set the phone into a time-zone-setting reverie.

Tentatively, though, we'll say that iOS 5, not the iPhone 4S hardware, appears to have a significant effect on battery life. See the video below for more.

Here are the battery percentages we saw during our rundown test.