Reviewers are already uncovering details in the iPhone 15 series that Apple didn’t mention at the keynote, and one recently uncovered feature might significantly increase the battery life of your iPhone.

To be clear, we’re not discussing battery lifetime on a single charge here; rather, we’re discussing how quickly your battery deteriorates over the course of its whole life. For instance, anyone still holding onto a six-year-old iPhone X is probably aware that charging from 100% to flat no longer requires nearly as much time as it did when the device was brand-new.

According to MacRumors, the new iPhone 15 series’ models get a special ‘80% limit’ option in their battery options menus. This additional 80% limit acts as a new hard ceiling on where charging caps out. “Optimised battery charging” was previously in place to maintain your iPhone’s battery at 80% overnight, until you were about to get up (at which time it would finish charging up to 100%).

Of course, by just charging your iPhone to 80% rather than 100%, you’re giving up some daily longevity, but if it means the phone will be content to give out the same amount of use each day for a longer period of time overall, isn’t that a net win for users?

Here’s how to activate it if you agree with the addition of this new function and wish to use it for your own gain.

Once enabled, you won’t need to tinker with the 80% limit function until you want to switch back to the earlier-mentioned “optimised battery charging” or turn it off entirely. It can be found quite easily within your Settings menu.

Opening Settings

Locate the Settings app from your home screen; it has a three-spoked gear with concentric gears inside as its icon. It resides by default on your main/first home screen. To open it, tap on it.

Battery Tap

Once the Settings menu is visible, look for a section labelled Battery. It’s probably situated between Privacy & Security and Exposure Notifications. Touch Battery.

Select Battery Health and Charging

You’ll find toggles to enable Battery Percentage and Lower Power Mode on the Battery settings page. Below those toggles, you’ll see an entry labelled Battery Heath & Charging; tap on that entry to continue.

Select Optimise Charging

To change this behaviour, go to the next screen by tapping on “Charging Optimisation,” which is set to “Optimised” by default. This setting adjusts charging overnight based on your daily usage habits.

Click 80% Limit.

Three power options will now appear: “Optimised Battery Charging,” “80% Limit,” and “None.” Swipe up to get back home after tapping on the 80% Limit to activate your iPhone’s most recent charging optimisation option.

You should no longer see your iPhone’s charge level rise above 80% when you plug it in to turn it on.