iPhone battery health and charging practices — looking for official guidance

I 100% concur with LD150. There's no need to overthink this. The phone is designed to manage its battery.

deedy_89 wrote:

I chose this model simply because I don’t like large phones, and at the time it was the smallest new iPhone available.

The smaller the phone, the smaller the battery. And yes, over time the battery capacity declines. Check yours in Settings>Battery>Battery Health>Maximum Capacity. It's its 80% or below, you need a new battery. It sounds as if you may be due. Two to three years is pretty standard for battery life.

Despite being a light user, the battery performance has declined noticeably. I don’t use Instagram, TikTok, Snapchat, or similar apps. I don’t game, I don’t do heavy video streaming, and I don’t use the camera constantly. My usage is limited to calls, messages, WhatsApp, Spotify, Notes, and Files. Even with this relatively modest usage, the phone now requires charging more than once per day.

That sounds like an aging battery to me.

Lately, I’ve also been keeping the phone in Low Power Mode most of the time in an attempt to extend battery life, and I’m unsure whether this is considered a good long-term practice or simply a short-term workaround.

It won't hurt anything. And, because you're using less power, the battery will last a bit longer.

Over the years, I’ve encountered a lot of conflicting advice, including recommendations such as waiting until the battery drops below 20% and then always charging to 100%, and I’m unsure whether this guidance is still valid for modern iPhones.

No, that is not valid advice for modern lithium-ion batteries. In fact, 20% is about when you should plug it in. Letting it go below that is not ideal. How much you charge it is really a matter of how much time you have.

You may want to look as this overview. It has good advice and links to Apple's offical documentation.

When to charge your iPhone or iPad - Apple Community

The Adaptive Power feature on new phones is frankly, amazing, by the way.

There will be a number of opinions in this Pandora's box! And you didn't evaluate considerable decline.

Here is mine.

Charge every night, all night, to 100% with optimised charging on. Charge limit is merely a placebo.

If a light user has to charge more than once a day there is a rogue app installed.

Keep the phone out of hot and sunny conditions like on a car dashboard.

In the end it is usage that ages batteries.

Hello deedy_89,

The more charge cycles your battery completes the faster it ages. Charging just to 80% nightly has worked best for me keeping my charge cycles to a minimum on my iPhone 17PM. How you use your iPhone should determine if you want to charge nightly to 100% with optimize charging turned on. See if this article on Lithium batteries is helpful to you.

Batteries - Why Lithium-ion? - Apple

"Over the years, I’ve encountered a lot of conflicting advice, including recommendations such as waiting until the battery drops below 20% and then always charging to 100%, and I’m unsure whether this guidance is still valid for modern iPhones."

That advice was for NiCad and even NiMh batteries to avoid charge memory.

I have an SE3 which I use as an Apple Music server overnight (tinnitus!) In the morning it is at about 80%. It goes on charge every morning, optimised, til the evening.

My wife's iphone SE bought at the same time is hardly used. It drops to 85% by evening by just being an iphone. That's what an idle phone uses. It goes on charge all night every night, optimised, til morning.

After a year battery health on both phones is 98%

It is usage, not charging regime, that affects ageing.

Search for accessories that have completed MFi certification. Once an accessory has completed MFi certification requirements and is reported to Apple as sold/distributed, it will be searchable in our public database of authorized Lightning, headset, charging, iAP-enabled, and Find My network-enabled accessories.

Learn how to identify counterfeit or uncertified Lightning-based accessories.

You may try this (The suggestion is intended as a guide to help you find the right options and should not be interpreted as an endorsement or promotion of any product. Please conduct your own research and make an informed purchasing decision.) --> Apple Mfi-Certified, Type C Female to Lightning Male OTG ...

By the way, Apple Certified experts generally don't visit here, we are all users.