Yellow battery means Low Power Mode is on

When your iPhone's battery icon turns yellow instead of green or red, it means Low Power Mode is active. This is a setting you can turn on manually, or your phone can turn it on automatically when the battery drops to 20 percent.

Low Power Mode reduces power consumption across your phone by limiting background activity, reducing performance, and dimming the display slightly. It extends how long your phone will run before it needs to charge. The yellow color is your phone's way of telling you that it is in this power-saving state.

You will see the yellow battery icon in the top right corner of your screen whenever Low Power Mode is active, no matter what your actual battery percentage is. A phone at 50 percent with Low Power Mode on will show yellow; a phone at 19 percent without Low Power Mode on will show red.

Key Takeaways

  • Yellow battery means Low Power Mode is turned on, which slows some phone functions to save power.
  • Low Power Mode can be turned on manually in Settings, or your phone will turn it on automatically at 20 percent battery.
  • When Low Power Mode is on, background app refresh, automatic downloads, and some visual effects are reduced.
  • You can turn Low Power Mode off at any time by going to Settings > Battery, even if your battery is low.

How to turn Low Power Mode on or off manually

You can switch Low Power Mode on or off whenever you want, regardless of your battery level. Open Settings, then tap Battery. You will see a toggle switch next to "Low Power Mode"—tap it to turn it on or off.

You can also control Low Power Mode from Control Center. Swipe down from the top right corner of your screen (or up from the bottom on older iPhones), find the battery icon, and tap it. The icon will turn yellow when Low Power Mode is active.

When you manually turn on Low Power Mode, it stays on until you turn it off—even if you charge your phone to 100 percent. If your phone turns it on automatically at 20 percent, it will turn off automatically once you charge to 80 percent.

What Low Power Mode actually does to your phone

Low Power Mode makes several changes to how your iPhone runs. Background app refresh is limited, so apps do not check for new messages or updates as often. Automatic downloads of apps and updates pause. Mail no longer fetches new messages in the background—it only checks when you open the Mail app.

Visual effects like animations and transitions are reduced. Some features like Hey Siri voice set up may not work. Location services are less precise. Video streaming quality may be lower. However, you can still make calls, send messages, and use your phone normally—it just runs a bit slower and checks for updates less often.

Performance is reduced slightly, so apps may take a moment longer to open and tasks may process more slowly. This is intentional: by slowing down non-essential functions, your phone uses less power overall.

When your phone turns on Low Power Mode automatically

Your iPhone will automatically turn on Low Power Mode when your battery reaches 20 percent. You will see a notification asking if you want to enable it. If you tap "Enable," Low Power Mode turns on. If you tap "Don't Enable," your phone will ask again at 10 percent.

Once you plug in your phone and charge it to 80 percent, Low Power Mode turns off automatically. If you manually turned it on before the battery got low, you have to turn it off yourself—it will not turn off automatically when you charge.

You can change when Low Power Mode turns on automatically by going to Settings > Battery > Low Power Mode and adjusting the threshold, though most iPhones do not offer this option and use 20 percent as the fixed point.

Why your phone uses Low Power Mode even when plugged in

If Low Power Mode is on while your phone is charging, it stays on. Your phone does not automatically turn off Low Power Mode just because it is plugged in—only when the battery reaches 80 percent. This means you might see a yellow battery icon even while your phone is actively charging.

This is normal and not a problem. Low Power Mode will continue to reduce background activity and performance until you either turn it off manually or the battery reaches 80 percent. If you want to use your phone at full speed while charging, you can turn off Low Power Mode in Settings or Control Center.

The difference between yellow, green, and red battery icons

Yellow means Low Power Mode is on. Green means your phone is plugged in and charging, or fully charged, and Low Power Mode is off. Red means your battery is very low (usually under 20 percent) and Low Power Mode is off.

The color tells you two things: whether Low Power Mode is active (yellow means yes, green or red means no) and whether you are plugged in (green means yes, yellow or red means no). A phone at 5 percent battery with Low Power Mode off will show red. A phone at 50 percent battery with Low Power Mode on will show yellow.

Frequently Asked Questions

Does Low Power Mode slow down my iPhone?

Yes, slightly. Apps open a bit slower, animations are reduced, and background tasks run less often. For most everyday use like texting, calling, and browsing, you will not notice much difference. If you use your phone for gaming or video editing, you may feel the slowdown more.

Will Low Power Mode damage my battery?

No. Low Power Mode is designed to reduce strain on your battery by limiting power-hungry tasks. Using it regularly does not harm your battery health. In fact, keeping your battery from draining completely can help it last longer over time.

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

Yes. You can make calls, send messages, browse the web, and use most apps normally. Some background features work less often, and performance is slightly reduced, but Low Power Mode does not prevent you from using your phone.

Why did my phone turn on Low Power Mode without asking?

Your phone turns on Low Power Mode automatically when the battery reaches 20 percent. If you did not manually enable it, it turned on automatically. You can turn it off anytime in Settings or Control Center, even if your battery is still low.

Does yellow battery mean my phone is about to die?

Not necessarily. Yellow just means Low Power Mode is on. Your battery could be at 90 percent or 10 percent—the yellow icon does not tell you the actual percentage. Check your battery percentage in Settings > Battery to see how much charge you actually have left.