iPhone Battery Limiter Anecdata ⇥ icloud.com

Juli Clover’s experiment last month created fertile ground for ample anecdata about whether capping the battery at 80% of its capacity leads to better longevity. This sort of stuff fascinates me.

So here is what I did with my evening: I looked through the first ten pages of the relevant MacRumors Forums thread, the links in Michael Tsai’s roundup, and figures I was emailed by readers. I only looked at reports from the iPhone 15 family of models for a more valid comparison, and only recorded those with capacity, cycles, and an indication of whether limiting was turned on.

Is this data? Barely! I did not factor anything else into this — not charge method, and not the specific iPhone 15 phone model. If someone said they used the 80% charging limit for most of the phone’s life apart from vacationing, I counted that as using the limit. Also, this is a survey of people who felt compelled to comment on a forum thread about battery statistics, so it is wildly skewed. It can barely be called “statistics” because these numbers are so noisy, but it is fun. Roll with it.

Here is my Numbers spreadsheet with a little over a hundred reports. As I was entering it, two things struck me:

  1. Far more of the people reporting 100% remaining battery capacity after typical use have turned on the charge limiter.

  2. People who use the charge limiter seem to also use their phones less but, critically, the 80% limiter appears to help lighter users.

The latter is maybe a little bit too obvious, and it is probably the biggest factor: if you use more of your battery more often, it will wear out faster. But this is something to consider. If you regularly find yourself with plenty of charge remaining at the end of the day, this collection of anecdotes suggests you should think about turning on the capacity limiter. If you are a light user, you may be able to stretch out the life of your battery and keep the same phone for longer.

If you are a heavier phone user, though, you might just be compelled to replace your battery more often regardless of your settings.

Update: “jawbroken” on Bluesky made a chart. (You may need to log into Bluesky to see it.)