Three ways to turn it on
Settings → Battery → Low Power Mode is the direct route. Faster: add the Low Power Mode control to Control Centre from Settings → Control Centre, then it is one swipe and one tap. You can also just ask Siri to turn on Low Power Mode.
iOS also offers it automatically when you reach 20% and again at 10%, which is the prompt most people know it by.
What it actually changes
It reduces or pauses background app refresh, automatic downloads, mail fetch, some visual effects, and auto-lock drops to 30 seconds. On models with ProMotion, the display refresh rate is capped, which is a significant part of the saving. 5G use is reduced where possible.
What it does not do: it does not stop notifications, block calls or messages, or limit anything you actively use. Apps you open work normally. The battery icon turns yellow while it is on.
Why it switches itself off
Once the iPhone charges back above 80%, Low Power Mode turns off automatically and cannot be prevented from doing so through Settings. This catches people who want it on permanently.
The workaround is an automation, below. There is no toggle that makes it stick.
Making it automatic with Shortcuts
Open Shortcuts → Automation → new automation → Battery Level, set it to fall below a threshold you choose, and add the action Set Low Power Mode to On. Turn off Ask Before Running so it fires silently.
To keep it on permanently, create a second automation triggered by Low Power Mode turning off that turns it straight back on. That defeats the 80% reset. A third, triggered by charger connection, can turn it off while you charge if you prefer.
Using it as a default
There is no downside to running it all the time beyond slightly less background freshness and a lower refresh rate. On an older iPhone with a worn battery it can be the difference between reaching the evening and not.
On a phone whose battery health is below 80%, this is a genuine mitigation rather than a workaround — but it is mitigation. Our replacement guide covers the actual fix.
When to turn it off
Before something that depends on background work: a long navigation route, a workout you want tracked accurately, a large download you want to complete while the screen is off, or an iOS update.
Our battery life guide covers the settings that help without any of these trade-offs.
Frequently Asked Questions
How do I turn on Low Power Mode?
Settings → Battery → Low Power Mode, or add the control to Control Centre for one-tap access. Siri can also do it.
Why does Low Power Mode turn itself off?
It switches off automatically once the iPhone charges above 80%. A Shortcuts automation is the only way to keep it on.
Does Low Power Mode stop notifications?
No. Notifications, calls and messages all work normally. It reduces background activity and visual effects.
Can I leave Low Power Mode on permanently?
Yes, with a Shortcuts automation that re-enables it. There is no harm in running it all the time.