Testing the iPhone 4S' battery life

The Internet is awash with reports of poor battery life for the iPhone 4S, but CNET Labs hasn't had the same experience yet. Here's why.

Kent German Former senior managing editor / features
Kent was a senior managing editor at CNET News. A veteran of CNET since 2003, he reviewed the first iPhone and worked in both the London and San Francisco offices. When not working, he's planning his next vacation, walking his dog or watching planes land at the airport (yes, really).
Kent German
3 min read

When Apple unveiled the iPhone 4S last month, company execs proudly promised that the new handset would offer the longest battery life of any iPhone yet.

Apple fans greeted the news warmly, but now, less than three weeks after the 4S went on sale, some iPhone owners are seeing red. And by that I mean the red battery indicator on their devices.

As CNET's Josh Lowensohn reported last week, Apple is investigating user complaints that the iPhone 4S' battery is draining faster than it should. Though the company claims that the 4S will deliver 8 hours of 3G talk time, 6 hours of Web browsing, 10 hours of video playback, and 40 hours of music playback, more than a few 4S owners are finding that their handsets last just a few hours. And that's with minimal use and with power-draining features disabled.

The stories are troubling, partly because the 4S has performed well in CNET Labs tests. Consider that in our talk time tests, our review handset lasted a very respectable 9.2 hours on a single charge. What's more, in our media tests conducted last week and through the weekend, we came away with 8.2 hours of video playback and 64 hours of audio playback. So except for video playback, our results beat Apple's rated times.

It's not surprising then that since I first posted our results, I've heard from a handful of CNET readers who've asked how we could have achieved them. It's a very good question, particularly when your phone is dying too quickly. Yet, the answer lies in how we use our phones.

Keep in mind that CNET Labs tests are designed to compare specific manufacturer promises. So when a manufacturer says a phone will last a certain time while making calls or playing music, we'll run those tests to see how well those claims bear out (you can read more about the process here).

When a phone is performing one function, and one function only, it's not uncommon for it to last a long time. Smartphone manufacturers, however, have struggled to maximize battery life while adding as many features as they can. Indeed, with the typically large, power-hungry displays and always-on features like GPS, Wi-Fi, and Bluetooth, a nightly charge has become a ritual for most smartphone owners.

Similarly, most people don't use a phone for only one thing for hours at a time. Rather, they're using the handset for many different things throughout the course of the day. They're multitasking with several features running in the background, the display is constantly on, and they're tapping at the screen every few minutes. By all means, it's a very different scenario.

Properly simulating this real-world user testing is difficult because we haven't established a benchmark for doing so. We're working on it, though, and in light of the recent user complaints about the iPhone 4S' battery life, I'll be using a 4S as my primary phone over the next few days to see how it fares when I use it to make calls, play games, send texts and e-mails, use applications, and browse the Web, all at once.

CNET is taking these complaints seriously, and while we haven't had a poor iPhone 4S battery experience so far, we're watching to see if we do. We're also looking into reports that the iPhone 4S is draining too fast even when it's left alone in standby mode. And in the meantime, check our this helpful post from CNET editor Sharon Vaknin on maximizing your iPhone 4S' battery life.