Okay, I’m speaking up. I’ve seen one too many articles about people trying to keep their iPhone batteries at an 80 per cent charging limit to help maintain battery life. I wish that was how it worked, but that feature is only to help your iPhone reduce charging cycles if you have it plugged in all day.
For example, if you’re a delivery driver and need to keep your phone plugged into your car for CarPlay all day, this feature is for you. It’s also helpful for iPads that will only be used as cash registers or stay plugged in at a desk. If you’re a regular user who charges at night or when your battery gets low, this feature does nothing but wear out your battery faster.
Running your battery down and recharging it back up is actually worse for your phone than just trying to maintain a charge for as long as you can. The real key to longer battery life is fewer charge cycles. The less you do, the longer your phone’s battery will last. Other factors like heat and cold can matter a bit, but nothing is as impactful as a complete battery cycle.
I’ve linked the most interesting battery study video I’ve seen below, which comprehensively examines the impact of charging, wireless charging, heat, and more on smartphone batteries.
In that test, they’re using iPhone 13 models. I will say that I found the iPhone 14 and 15, especially the Pro models, would get super hot while wireless charging sometimes, and I do feel like that might have led to worse-than-average battery longevity. I’ll also say that in my use, the iPhone 16 and 17 models appeared to remedy this problem since they didn’t get as hot during wireless charging. This is particularly impressive because those devices also came with faster wireless charging speeds than the 14 or 15.
If you’ve read any of these stories about people living two years with their phones set to an 80 per cent limit, you’ll see that it didn’t work out well for them. So, unless you need to have your phone plugged in all the time, don’t use a charging limit. If your phone is plugged in excessively, the operating system will even notify you that you might benefit from a charging limit.
Part of all this confusion stems from Apple’s support page. The charging limit section is subtitled, “Improve battery lifespan with Charge Limit.” This is true, but not for everyone, so it’s a bit misleading. That said, you have to turn off ‘Battery Optimization’ to apply a charging limit, and the same support page says, “Turning off charging optimizations can increase wear on your battery and reduce its lifespan.” That said, it’s not in giant letters like the other sentence I referenced.
Ideally, Apple could clarify the support page so that people will stop applying battery charging limits for no reason. I’ve spent years trying to repair the damage Android multitasking has done to iPhone users who think they need to keep closing their apps, and I really don’t want to spend another five years explaining this new tech myth to people.
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