iPhone 5 terrible battery drain on Verizon w/ iOS 7

Iosbattery_medium

via Ars Technica

Apple’s iOS 7 debuted today to strong reviews and favorable reception. The performance improvements are significant, even on older hardware, though reviews indicate that the three year-old iPhone 4 struggles with the new animations and transitions. But the odd thing here is that one phone — the Verizon iPhone 5 — takes an absolute wallop in battery life. All of the phones are negatively impacted by the iOS 6 to iOS 7 transition, but look what happens to the iPhone 5 under WiFi compared to iOS 6 and iOS 7.

These tests were conducted as part of Ars Technica’s hugely comprehensive review of the entire operating system, and what they show for the iPhone 5 is problematic for anyone looking to upgrade. We contacted Andrew Cunningham, author of the Ars review, who confirmed that the Verizon phone was tested twice, on both operating systems, with full factory resets in between each test. The numbers came out identically in each case.

There’s some difference in how each website does phone testing and it comes out in the various battery life figures. Anandtech pegs the iPhone 5 at 8.9 hours of battery life for WiFi tests in iOS 7 — midway between Ars’ 11.01 hours on iOS 6 and 7.4 hours on iOS 7. So how do we square the results, assuming nobody screwed up?

The joy of corner cases

Certain people have complained of poor battery life from iOS 7 since the OS went into beta, but no one appears to have built a database of which devices were having the most problems. We know iOS 7 uses more battery life in general — it’s possible that this problem is caused by specific test characteristics and a bit of customized Verizon software. Apple produces two versions of the iPhone 5 — the A1428 and the A1429. While the underlying hardware is typically very nearly identical, carriers do install custom software on a device to identify it to their own specific networks.

Alternately, it’s possible that a combination of webpage specific code, iOS 7 changes, or a WiFi bug have combined to keep part of the chip from dropping into sleep mode. If the WiFi radio is sitting open constantly, or a CPU core is spun up and looping rather than falling back to sleep after the page load, it would explain why the chip is blowing through its battery life in dramatic fashion. Unfortunately, it’s difficult to tell where the issue actually lies, and whether or not the Ars results are an odd anomaly or an indication of what Verizon iPhone 5 owners (or all iPhone 5 owners) can expect.

Issues like this, for the record, are why I personally don’t update my phone when Apple releases a new operating system. I got burned with iOS 4 and the Apple 3G — after the update, my phone was far slower, even when performing simple tasks like launching applications immediately after a reboot. Even resets and full installations didn’t help the problem. Each of Apple’s last few iOS launches has had issues of varying degrees, so it’s not surprising that we might see some problems here, as well.

Rather than declaring one side "right" versus wrong, I’d suggest a bit of practical caution. It’s obvious that in some cases, iOS 7 is hitting iPhone 5 battery life hard. Whether that reflects a software bug, corner case, or carrier oddity, it’s something that could make the upgrade experience less fun for someone who grabs the newest version without checking first. As always, your mileage may vary.

Personally, on my Verizon iPhone 5, iOS 7 battery life is significantly worse than 6.1.4. I'm down to maybe 6 hours of usage time vs 8 - 8.5 hours of usage time previously. I bought this phone in April.

Even standby time is worse, and I've already completely restored from scratch to iOS 7 in iTunes and set it up as a new iPhone.

What have your experiences been like?