Is 91% battery health normal for iPhone 15?

The battery in the iPhone 15 is designed to go up to 1,000 Charge Cycles before the Battery Health reaches 80%.

That works out to a 1% decline for every 50 Charge Cycles on the battery.

Your battery has completed 200 Charge Cycles divided by 50 = 4%. So, the Battery Health should be about 96% at this time instead of 94%. That's not bad, but it should be bit higher.

If you check the Battery Settings, you can see which apps are using up the most power.

First: Battery "Health" always degrades. You cannot change that. Like tires on a car, the rechargeable battery is a wear item and will lose capacity (health) over time regardless of what you do or don't do. Getting a little box to make electricity is a chemical process and the chemicals cannot continue the reactions that create power indefinitely.

Please do not obsess over an inexact and non-linear metric. "Health" is based on the AVERAGE initial capacity the battery is expected to produce, not the actual capacity it had when it came off the battery assembly line. vagaries onf any

"Average" means that, because my SE2020 arrived new with 102% health, some poor soul out there got one new that started at 98%.

As for non-linear, look at the health history on my iPhone SE 2020 from about Jan 2024 to present, drawn from the Coconut Battery utility:

The patten of leveling out around 85 % is something I've seen in other Apple devices. My older Macbook Pro that was new in 2013 still has the original battery and is only now bumping the 80% line. And it still has an acceptable runtime between recharging.

As for what to do, I'll share an observation I recent made with our two iPhones. Mrs AJ and I got them new the same day from our carrier, and set them up at the same time. I am diligent about charging mine every night while I sleep. Mrs AJ has those "oops! my battery is low!!" moments and charges hers in a way that defies finding a pattern in it.

Mine should be doing better, but the battery health of the two phones are within 1% of each other after 3.5 years of use.

Save you worries for something you can affect.

Bob Timmons wrote:

Yes, games use up a lot of power. So do social apps like WhatsApp, if you are using that app.

and hot batteries degrade faster

Temperature Effects on Li *** Battery Life:

• Capacity loss in standby applications is largely determined by temperature
• Annual capacity loss tends to decline as the battery ages
• 80% remaining capacity is generally not the end of a lithium battery's useful life, but recommended by Apple for replacement

I recommend to slow charge your iPhone to maximize the charge capacity, battery health and efficiency. ⚡️🔋

NOTE:

Temperature: Charge above -30°C and Discharge below 55°C

Battery Performance Tips:

• iPhone Battery and Performance.
• Check battery health and usage.
• Optimized Battery Charging.
• Maximizing Battery Life.
• Use Low Power Mode.
• About battery usage.
• Show battery percentage.

Click ▶︎ iPhone User Guide. 📖

Good luck! 👋🏼😉

Yes, games use up a lot of power. So do social apps like WhatsApp, if you are using that app.

My theory - because iphone batteries level out at 83-85% is why apple offers to replace them at 80% in applecare+