iOS 18.1 update worsen your iPhone battery health? Don't let this spec fool you

With every iOS update, people flood social media to complain about how the update has destroyed their iPhone's battery health, with the health figure dropping precipitously immediately after installation.

If you're someone who knows, without looking, what your iPhone's battery health is, then you need to stop obsessing over this number.

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Don't know the state of your iPhone's battery health? Grab your iPhone, tap on Settings, and head over to Battery and then Battery
Health. Here you'll find a Maximum Capacity number. The lower the capacity, the less usage you're going to get between charges.

However, the Maximum Capacity number is not a measure of overall battery wear. Instead, it is "a measure of battery capacity relative to when it was new." Put another way, it's how much power the battery can hold.

Also: Here's what Apple doesn't want you to know about your iPhone's battery

Even I've experienced a big drop in battery health. Before installing iOS 18.1, my battery was at 100%; now it sits at 99%. The slide towards the end of its life surely, is now underway.

I encountered 200+ recharge cycles before it ticked down to one percentage point, which is relatively good, no matter how you look at it. At that rate, it would take some 4,000 recharge cycles to get to 80%, (the point Apple considers it worn). It'll never hit this number. Even Apple's optimistic figures say that 1,000 recharge cycles are the best you can get from the iPhone 15 or iPhone 16. 

And this is just one of the flaws of this figure.

Another problem is that some things can cause this figure to be miscalculated. Keeping your iPhone on charge all the time or never letting it fully charge can also cause the Maximum Capacity figure to display an incorrect value. So when a new update is installed and the calibrations are recalculated, it results in the number dropping a few percentage points. 

This isn't wear; it's the figure being recalibrated.

Also: 5 reasons to update your iPhone to iOS 18.0.1 right now

So what can you do to prevent this problem? Simple. Either use Optimized Battery Charging or set a charge limit below 100% (to do this, tap on Settings, head over to Battery, and then Battery Charging). This way, the battery never sustains a long-term overcooking at 100% charge but gets the occasional boost to 100%, which is needed for good battery health and calibrating battery health. 

And then stop worrying about it.