iPhone 14 Basic, Maximum Capacity Battery

Hezzers22 wrote:

I have an iPhone 14 Basic activated in 2022. I have been very careful to take all the necessary steps to protect my battery life. After a few months, I noticed in -Battery Health & Charging - Maximum Capacity that I was at 96% Maximum Capacity. Flash forward to February 2025 and I am at 85%. This is distressing to me seeing that I have done everything to prevent this from happening. My phone works FINE. I have had no issues whatsoever, but I am concerned. I bought this phone outright, I am in Italy and Apple Care works differently here and I would not be covered for a new battery even if I had Apple Care. Thoughts? Suggestions for preventing the battery from going lower than 85% Kind regards, Heather M.

There is no way to prevent it happening. Batteries are consumables; they lose a little capacity every time they are discharged, then recharged. On average this works out to about a 1% loss for every 25 “full charge cycles” (50 for iPhone 15 and later) . As one example, if you charge the phone overnight, every night (and that is what you should do; it is a best practice), it starts the day at 100%. If it drops to 20% by the end of the day before you charge it again overnight that counts as 0.8 full charge cycles (20% to 100%), or about 24 full charge cycles per month of use. For this example your battery capacity will lose about 1% per month. Of course, if the end-of-day level is higher than 20% the capacity loss will be a little less, and if it is lower than 20%, or you charge it during the day, the capacity loss will be higher.

The absolute best way to get maximum use on a charge, as well as slow the decline of battery capacity long term is to enable Optimized Battery Charging (Settings/Battery/Battery Health) and charge the device overnight, every night. The battery will fast charge to 80%, then pause. During the nighttime pause the phone will use mains power instead of battery power, allowing the battery to “rest”, and thus reducing the need to charge the battery quite as often. The phone will resume charging to reach 100% when you are ready to use your phone; it will “learn” your usage pattern. If you enable iCloud Backup (Settings/[your name]/iCloud - iCloud Backup) the phone will back up overnight also, assuring that you can never lose more than the current day’s updates. Here's more information→About Optimized Battery Charging on your iPhone - Apple Support

Yes, charging overnight is the best way to extend the life of the battery, for the reasons I gave, and is a lot less fuss than monitoring your charging manually. After all, you have a phone, not a battery charger.

A couple of things to consider:

"Health" is inexact.

It is defined as the current battery capacity divided by the design capacity when new. The problem is the value used for design capacity is an AVERAGE of all batteries of that model, not the ACTUAL initial capacity of your battery. My 2020 SE arrived showing Health at 102.3%. Averaging means there is some poor soul out there whose iPhone started at 98%.

"Health" is non-linear

This is the complete battery health history of my SE 2020 since unboxing on 1 November 2021, as tracked with the Coconut Battery app. Although the trend is downward, note that the data points are non-linear:

That can be rounding but in some Apple devices I've seen a 10% swing in two months. It's also my observation that the rate of capacity depletion seems to slow at about the mid-80's.

This has taught me not to obsess over "health."

We bought two identically specced SE2020s in late 2021. I am diligent about charging every night, seldom during the day. Mrs AJ is more "free-spirited" about charging hers. She does not charge every day, and the time of day varies. It seems more on an, "Oops! I’m low!" basis.

While doing the 18.3.1 updates the other day, I checked the "health" of both batteries. Both were 85% after 39 month of use. Go figure. I won't change my charging patterns because of that, but I suspect Mrs AJ won't either!

Don't stress of the battery unless it won't hold a charge or the phone starts giving you battery advisories.