'ZDNET Recommends': What exactly does it mean?
ZDNET's recommendations are based on many hours of testing, research, and comparison shopping. We gather data from the best available sources, including vendor and retailer listings as well as other relevant and independent reviews sites. And we pore over customer reviews to find out what matters to real people who already own and use the products and services we’re assessing.
When you click through from our site to a retailer and buy a product or service, we may earn affiliate commissions. This helps support our work, but does not affect what we cover or how, and it does not affect the price you pay. Neither ZDNET nor the author are compensated for these independent reviews. Indeed, we follow strict guidelines that ensure our editorial content is never influenced by advertisers.
ZDNET's editorial team writes on behalf of you, our reader. Our goal is to deliver the most accurate information and the most knowledgeable advice possible in order to help you make smarter buying decisions on tech gear and a wide array of products and services. Our editors thoroughly review and fact-check every article to ensure that our content meets the highest standards. If we have made an error or published misleading information, we will correct or clarify the article. If you see inaccuracies in our content, please report the mistake via this form.
How to turn on 80% charging limit on the iPhone 15 to save battery health
The iPhone 15 series is officially available, and whether you already have a device in hand or are anxiously waiting for one, a recent feature discovery should be at the top of your initial set-up agenda.
The feature is called "80% Limit" and is tucked within the deeper end of the iPhone 15's Battery settings. When toggled on, the iPhone will limit its charging capacity to 80% instead of the normal 100%.
Also: Want the fastest iPhone? Choose this model on this network
While Apple doesn't actually explain why this feature exists, it's safe to assume that the charging cap is a direct response to the recent comments about the iPhone 14's battery degradation. These aren't fan theories, unfortunately; it's just the nature of lithium-ion batteries found in iPhones and other devices, with the maximum capacity slowly degrading every time it completes a charge cycle.
Capping the iPhone 15's charging to 80% reduces the likelihood of battery degradation, though it may not always be in your best interest to have the feature turned on. More on that later.
How to turn on 80% Limit on the iPhone 15
What you'll need: At the time of writing, 80% Limit is only available on the iPhone 15 series, which includes the iPhone 15, iPhone 15 Plus, iPhone 15 Pro, and iPhone 15 Pro Max.
Also: Your Apple device may be eligible for a major software update. How to check and download
The feature is clearly not processor-exclusive, as the non-Pro models operate on an A16 Bionic chip versus the A17 Pro on the more expensive iPhones. Therefore, the chances of Apple extending the feature to older models are still likely.
1. Access Battery Health & Charging settings
First, open up the Settings app and scroll down to the Battery tab. Then, tap on Battery Health & Charging.
Tip: A new iPhone 15 should be at 100% Maximum Capacity.
2. Toggle on 80% Limit
Now tap into Charging Optimization and you'll be presented with three options:
- Optimized Battery Charging: Prompts the iPhone to trickle charge up to 80% overnight and then tops up to 100% as you're about to wake up.
- 80% Limit: Caps the charging at 80%. Apple says the iPhone will occasionally charge to 100% in order to maintain a more accurate battery state-of-charge estimate.
- None: Keeps the iPhone's charging capabilities flexible.
Tap on 80% Limit to turn it on.
Also: Battery bad after installing iOS 17? Try these 7 tips
While you're on the Battery Health & Charging screen, you'll also find the maximum battery capacity of your iPhone, which, if it's an iPhone 15, should be at 100%. If your device shows a lower value, reach out to Apple support as there may be a potential defect with your battery.
When you should (and when you shouldn't) use 80% Limit
You should use 80% Limit if...
- You want to preserve the battery health of your iPhone, whether it be for longevity's sake or better resale value.
- You're able to get through a day of average to high usage without battery concerns. This is mostly the case with the larger iPhone models, iPhone 15 Plus and iPhone 15 Pro Max.
You shouldn't use 80% Limit if...
- You're concerned that 80% battery is not enough for a day's use. Perhaps you're traveling and access to power sources is limited or need to use more power-intensive tasks like video capturing, GPS navigation, and gaming.