Optimised charging and the 80% limit: how to extend battery life

Optimised (adaptive) charging is a feature that learns your routine and tops the phone up to 100% only just before you pick it up. An 80% limit (or 85-90%) stops charging at a set level to reduce battery wear.

A battery lasts longer if it is not kept at 100%

In plain words

Imagine a balloon. Blow it up to the limit and leave it that way all night, and the rubber tires and stretches over time. Inflate it to 80% and it lasts much longer. A lithium-ion battery is similar: it "tires" most at 100% and when hot. Optimised charging avoids keeping it "inflated to the limit" for long.

How it works

The phone remembers when you usually unplug it.
It charges quickly to 80%, then pauses.
It tops up the last 20% closer to your wake-up time.
The "80% limit" mode simply stops charging above the set level.
Less time at 100% and lower temperatures mean slower wear.

The phone tops up to 100% just before you wake up

Where you'll see it

On iPhone: Optimised Battery Charging and an 80-100% limit on newer models; on Samsung: Battery Protection with modes; on Pixel: Adaptive Charging and a limit; and similar features on Xiaomi, OnePlus and others. Laptops and some tablets have it too.

Does it matter when buying

Yes, I recommend turning it on. If 80% gets you through the day, the limit will noticeably extend battery life. If you have a long day ahead without a socket, you can switch the limit off temporarily and charge to 100%. For phones that are always plugged in (say, as a car navigator), the limit is especially useful.

Myths

Myth: The 80% limit permanently reduces usable capacity. Reality: You can turn it off at any time.
Myth: Modern batteries do not mind 100%. Reality: The controller prevents overcharging, but sitting at 100% for long still speeds up wear.

FAQ

Should I turn on the 80% limit?

If the charge is enough for you, yes - the battery will last longer.

Why did my phone stop at 80% overnight?

That is optimised charging - it will finish by morning.

Does it work with wireless charging?

Yes, these features work regardless of how you charge.