Uncovering the iPhone Battery Slowdown

　　A battery problem with Apple iPhones has spawned eight lawsuits seeking class-action status against the handset maker, according to a Reuters report. The founder of a popular benchmark program shared his experience being among the first to identify the issue.

　　The lawsuits generally claim Apple failed to inform users about known performance issues that could be solved with a battery replacement, rather than buying a next-generation handset. For the past year, upgrades of iOS have intentionally slowed processors to avoid unintended shutdowns when chips demanded power spikes an aging battery could no longer deliver.

　　The problem came to light earlier this year for John Poole, founder of Primate Labs, the developer of Geekbench. He saw a spike in complaints about slowing performance from iPhone users coupled with 40 percent declines in Geekbench numbers.

　　“Whenever a new version of the iPhone comes out, we get complaints about older iPhones that feel slow. Apple does more with new OSes, and older phone can’t necessarily keep up…it’s not nefarious, and we are used to a certain level of these complaints…[but] this year we saw more of those complaints coupled with decreases in Geekbench,” Poole said in an interview.

　　When a user posted on Reddit that his iPhone’s performance returned to normal after he replaced its battery, “I started digging into the results and that’s when I realized there was something going on,” Poole said.

　　He tapped into his database of 6 million Geekbench scores, plotting performance of different versions of the iPhone using different versions of iOS. Handsets using iOS version 10.2.1 and later revealed an anomaly. Rather than a single distribution around an average peak performance, they also showed the highest peak followed by multiple lower peaks.

　　“The conclusion we drew was 10.2.1 introduced some change that effected performance in a systematic way in a significant number of phones,” Poole said.

　　After he published his results, Apple publicly responded to growing questions with a statement posted by National Public Radio and other a Web sites:

　　“Lithium-ion batteries become less capable of supplying peak current demands when in cold conditions, have a low battery charge or as they age over time, which can result in the device unexpectedly shutting down to protect its electronic components.

　　"Last year we released a feature for iPhone 6, iPhone 6s and iPhone SE to smooth out the instantaneous peaks only when needed to prevent the device from unexpectedly shutting down during these conditions. We've now extended that feature to iPhone 7 with iOS 11.2, and plan to add support for other products in the future," Apple said

　　The battery problem was a flip side of the iPhone’s lead in overall smartphone performance, Poole explained.

　　“Apple chased single-core performance to an insane degree. They were far ahead of Android, but it came at a cost of power consumption — they require more voltage, and as a battery ages it cannot supply the needed voltage level,” he said.

　　“I don’t think this is nefarious on Apple’s part. They made the right call, but they should have communicated it to users more clearly,” Poole said. Over the course of “about three months a lot of users thought their iPhones were broken and we could only say the phone was slow but we did not know why. It caused a lot of frustration for users,” he added.

　　Indeed, even Poole’s wife experienced the slow down on her handset, “and she is not the most demanding of iPhone users,” he quipped.

　　Now that Apple has confirmed the cause of the problem, users have a better understanding of their options. One teardown expert, iFixit, was quick to offer a set of 11 battery upgrade kits ranging from a $16.99 kit for the iPhone 4 to a $49.99 version for the iPhone 7 Plus.

　　The crew at iFixit performed their own tests on four iPhone 6 and 6S models used by staff. The phones had inconsistent performance levels that varied from ten to 60 percent less than a new phone.

　　“We swapped the batteries, re-ran the benchmarks and it was a night-and-day difference,” said Jeff Suovanen, a teardown analyst at iFixit who helped perform the tests and posted a blog on the results.

　　“We’re used to seeing old phones with a new battery benefit from extended battery life, but having it increase performance is not something we traditionally see--but it’s a factor now,” he said.

　　“I think Apple is doing all they can to manage the situation the best they can, but they flubbed the communications so bad it got people wondering what was wrong with their phones…A lot of people thought they needed to replace their phones prior to uncovering this issue,” Suovanen added.

　　Meanwhile, Poole is investigating other Apple and Android products. So far he hasn’t seen other examples of the battery problem.

　　Android phones such as the Samsung Galaxy 6 he tested generally have “less aggressive single-core performance so they draw less power and tolerate an older battery,” he said.

　　The issue came to light after the iPhone 8 and X designs were largely complete, “so will be interesting to see if this affects future phones. We will watch the performance distributions and may start publishing these charts routinely,” he added.

　　Meanwhile, some users may aim for a windfall legal settlement from Apple. “Rather than curing the battery defect by providing a free battery replacement for all affected iPhones, Apple sought to mask the battery defect,” according to one complaint that Reuters quoted.