A yellow battery bar means Low Power Mode is on

Your iPhone's battery indicator turns yellow when Low Power Mode is active. This is Apple's built-in feature that reduces power consumption to extend how long your phone lasts on a single charge. The yellow color is intentional — it's a visual signal that your phone is running in a reduced-performance state.

Low Power Mode limits background activity, reduces screen brightness, and slows down some processor speeds. It kicks in automatically when your battery drops to 20 percent, but you can also turn it on manually at any battery level. The yellow bar disappears once you disable Low Power Mode or charge your phone above 80 percent.

Key Takeaways

  • A yellow battery bar indicates Low Power Mode is enabled, which slows your phone's performance to save battery life.
  • Low Power Mode activates automatically at 20 percent battery but can be turned on manually whenever you want.
  • You can disable Low Power Mode in Settings under Battery, or by tapping the battery icon in Control Center.
  • The yellow bar returns to the standard color once Low Power Mode is off or your battery charges above 80 percent.
  • Low Power Mode does not damage your battery or phone — it is a normal, reversible feature designed to extend daily use.

How to turn off Low Power Mode

The fastest way to disable Low Power Mode is through Control Center. Swipe down from the top-right corner of your screen (or up from the bottom on older iPhones), then tap the battery icon. It will turn gray, and your battery bar will return to its standard color within seconds.

If you want to turn it off permanently or check your Low Power Mode settings, go to Settings, tap Battery, then tap Battery Health & Charging. Toggle off the Low Power Mode switch. Your phone will return to full performance when ready, though battery drain will increase.

When Low Power Mode turns on automatically

Your iPhone automatically enables Low Power Mode when your battery reaches 20 percent. You'll see a notification asking if you want to turn it on. If you tap "Turn On," the battery bar becomes yellow and your phone enters reduced-performance mode.

If you dismiss the notification or tap "Don't Turn On," Low Power Mode stays off until you manually enable it or your battery drops to a lower threshold. Some older iPhone models may trigger Low Power Mode at different battery percentages, but 20 percent is the standard across current models.

What Low Power Mode actually does to your phone

Low Power Mode makes several changes to reduce power use. Your screen brightness may dim slightly, background app refresh pauses, automatic downloads stop, and some visual effects are reduced. Mail no longer fetches new messages automatically, and cloud photo syncing pauses. Your phone's processor also runs at a slower speed, which can make apps open slightly slower or animations feel less smooth.

Despite these changes, your phone remains fully functional. You can still make calls, send messages, browse the web, and use most apps normally. The slowdown is usually subtle enough that you won't notice it during everyday tasks. Low Power Mode is temporary — as soon as you turn it off or charge your battery, everything returns to normal performance.

Why your battery might drain faster than expected

If your battery is dropping quickly even with Low Power Mode on, several things could be happening. Background app refresh may still be running for certain apps, location services might be set to "Always" instead of "While Using," or your screen brightness could be higher than necessary. Check Settings > Battery to see which apps are using the most power.

Older batteries also drain faster than new ones. If your iPhone is more than two or three years old, the battery's capacity naturally decreases over time. You can check your battery's health in Settings > Battery > Battery Health & Charging. If the maximum capacity is below 80 percent, your battery may need replacement, though this is not urgent unless it's affecting your daily use.

Charging your phone while Low Power Mode is on

You can charge your iPhone while Low Power Mode is active — there's no harm in doing so. In fact, Low Power Mode will remain on until you manually turn it off or your battery reaches 80 percent, at which point it disables automatically. Many people leave Low Power Mode on while charging to maintain the reduced-performance state until they reach a full charge.

If you want Low Power Mode to turn off as soon as possible, charge your phone to 80 percent or higher, and it will disable automatically. Otherwise, you'll need to go into Settings or Control Center to turn it off manually.

Frequently Asked Questions

Does Low Power Mode damage my battery?

No. Low Power Mode is designed to protect your battery by reducing the strain on it. Using Low Power Mode regularly does not harm your battery or shorten its lifespan. It's a normal feature meant to extend how long your phone lasts between charges.

Can I use my phone normally with Low Power Mode on?

Yes. Low Power Mode keeps your phone fully functional for calls, messages, browsing, and most apps. You may notice slightly slower performance or dimmer brightness, but these changes are usually minor and won't prevent you from using your phone as usual.

Why did Low Power Mode turn on by itself?

Your iPhone automatically enables Low Power Mode when your battery drops to 20 percent. You should have received a notification asking permission first. If you tapped "Turn On," that's why it's active. You can disable it anytime in Control Center or Settings.

Will the yellow battery bar go away if I charge my phone?

The yellow bar will disappear once your battery charges above 80 percent and Low Power Mode disables automatically. If you want it to go away sooner, you can manually turn off Low Power Mode in Control Center or Settings regardless of your current battery level.

Is there a way to keep Low Power Mode on all the time?

Yes. You can leave Low Power Mode enabled indefinitely by keeping it turned on in Settings. Your battery will drain more slowly, but your phone's performance will remain reduced. You can turn it off whenever you want to return to full performance.