Slashdot Mirror
Apple's Alleged Throttling of Older iPhones With Degraded Batteries Causes Controversy (macrumors.com)
An anonymous reader shares a report: A Reddit post over the weekend has drawn a flurry of interest after an iPhone 6s owner reported that a battery replacement significantly increased the device's performance running iOS 11. The ensuing discussion thread, also picked up by readers in the MacRumors forum, has led to speculation that Apple intentionally slows down older phones to retain a full day's charge if the battery has degraded over time. According to TeckFire, the author of the original Reddit post, their iPhone had been very slow after updating to iOS 11, especially compared to their brother's iPhone 6 Plus, so they decided to do some research with GeekBench and battery life apps, and ended up replacing the battery.
When a phone is in a lower power state, power management can do several things to extend longevity: run the processor slower, dim the screen, operate the cellular radio in a lower power state. A worn out battery could potentially cause one or more of these things to happen.
Perhaps they could include a battery door so you can swap in a fresh battery at a small cost.
Comment removed based on user account deletion
And basically this is entirely invalidated by designing the phone such that the battery is not user-replaceable.
First of all, I've replaced batteries in iPhones many times and its incredibly easy. Here's a guy replacing one in four minutes. And you can even get a specific set of tools that will make it simple including the battery for around $25.
If that's too complicated there are thousands of places both local and online that will replace your battery for a very nominal fee.
It would take me probably half an hour to replace the PSU in my PC but I don't refer to it as being "not user-replaceable".
I've had to completely remove the motherboard to get the power supply out on several computers. Yes, that is a bad design.
This isn't about making the battery last longer. It's about making the phone work at all. It has to do with battery chemistry.
Old batteries don't just "last less". They also have an increased internal series resistance. That resistance actually limits the amount of power you can pull out of it. The more current you draw, the more energy is wasted as heat, and the lower the output voltage. As internal series resistance increases, it becomes physically impossible to get more than a certain amount of power out of the battery, and this limit also decreases as the battery drains during a given discharge cycle. It's a hard physical limit. The I-V curve just never hits your power target. If you try, your voltage sags and then the phone shuts down. This is what triggers a common syndrome in old devices, where the battery meter shows 30% but then you try to open up a CPU-intensive app and the device immediately shuts down. Chances are that's not the battery meter being wrong or miscalibrated: there really was 30% charge remaining in the battery. It just wasn't capable of handling that much power draw at that charge level. There's 30% charge remaining and there's a hidden limit as to how fast you can drain it.
It's almost certain that what Apple did here was start throttling phone performance when battery voltage sags below a critical threshold, to prevent hard shutdowns. On older batteries, this would appear as a performance limit as the battery empties. But it was never about making the phone last longer. It's just a physical limitation. The alternative is your phone shuts down. That's obviously not good.
The right solution, of course, is to have a notification or something that tells users when this is happening. Something along the lines of "Your battery cannot supply enough power to keep your device working at full performance. To maintain optimum performance, a battery replacement is recommended.".
Because the cables from the old PSU are run under the motherboard, through all sorts of openings in the chassis, and zip tied to everything? It's 5 minutes to actually change the power supply, but 25 minutes of cable management.