Lithium-ion batteries don't last forever and regular wear and tear will diminish its performance over time (usually after two years of regular use). The problem is that an aging battery doesn't just run for less time, it's also less capable of supporting peak energy loads.
This is the easiest way to check on your iPhone's battery health.
Since the iPhone 6, most every major iOS update has been accompanied by a spike in searches like "iPhone is slow". With the update, iOS dynamically manages the maximum performance of some system components when needed to prevent a shutdown. He concedes that replacing an iPhone's battery might be a bit trickier because of unique parts like the black pouch and tape, but that's still no reason for the number to be so high. And while Tonya's iPhone 6s, which is a year younger, still works, it has long suffered from the unexpected shutdowns.
Apple's slashed the cost of battery replacements in South Korea from KRW 100000 to KRW 34000 for now, but insiders believe the brand isn't suffering any losses from the lower rate.
Here's what I'd suggest: if you've got anything older than an iPhone 7, get the $29 battery change next time you're anywhere near an Apple Store. When the battery depletes to a certain point, the iPhone can randomly crash - and the slow down of old iPhones purportedly prevents this issue. Reading between the lines, it sounds like Apple is actually saying, "The batteries in these iPhones are underperforming in ways that we didn't expect and don't entirely understand".
Still, cheap battery replacement is the right thing for Apple to do.
To apologize for the issue, Apple reduced the cost of out-of-warranty iPhone battery replacements to only $29, from the original price of $79. Select the iPhone model you want to have tested.
Apple added the power management "feature" to iOS 10.2.1, which started to slow performance on iPhone 6 handsets. We'd like to see iOS act more like macOS does on laptops, where it puts a "Service Battery" message in the menu bar's battery menu. Interestingly, while Apple's initial announcement stipulated it would only make the offer available to customers "whose batteries need to be replaced", MacRumors has confirmed that the discount is available to all users, regardless of the current health of their phone's battery. But with the program being underway, the Apple customer can now visit any Apple Store or log on to Apple's support site and request to get their battery replaced at discounted price.
Concerned about waiting for weeks to get a discounted replacement battery for your iPhone? The Apple Store has all of the tools and resources required to run a diagnostic test on your phone's battery.