Yellow battery means Low Power Mode is on

The yellow battery icon on your iPhone appears when Low Power Mode is active. This is a setting you turn on yourself — it is not a warning that your battery is broken or failing. When Low Power Mode runs, your phone reduces performance and background activity to stretch battery life until you can charge.

The yellow colour is Apple's way of telling you that your phone is operating in a restricted state. Everything still works, but some features run slower or less frequently than normal. You can turn Low Power Mode off at any time by going to Settings > Battery, or by tapping the battery percentage icon in Control Centre.

Key Takeaways

  • Yellow battery means Low Power Mode is turned on, not that your battery is damaged or at critical level.
  • Low Power Mode reduces CPU speed, limits background app refresh, and turns off some visual effects to save power.
  • You can disable Low Power Mode in Settings > Battery or by swiping down from the top-right corner and tapping the battery icon in Control Centre.
  • Your iPhone will automatically turn on Low Power Mode at 20 percent battery unless you disable this setting, and again at 10 percent.

What Low Power Mode actually does to your phone

When Low Power Mode is on, your iPhone makes several changes to reduce power draw. The processor runs at a slower speed, which makes apps take longer to open and respond to taps. Background app refresh — the feature that lets apps update their content when you are not using them — turns off or slows down significantly.

Visual effects like animations and transparency are reduced or disabled. Mail stops fetching new messages as often. Location services become less precise. Video playback quality may drop. These changes are not permanent; they reverse the moment you turn Low Power Mode off.

The trade-off is real: your phone will last noticeably longer on a single charge, but it will feel slower while doing everyday tasks. For many people, the extra battery life is worth the minor slowdown, especially when you are away from a charger for most of the day.

How to turn Low Power Mode on and off

The fastest way is through Control Centre. Swipe down from the top-right corner of your screen (or swipe up from the bottom if you have an older iPhone). Find the battery icon — it looks like a lightning bolt inside a circle — and tap it. The icon will turn yellow when Low Power Mode is on, and return to normal when it is off.

You can also go to Settings > Battery and toggle the Low Power Mode switch. This route shows you your current battery percentage and lets you see which apps are using the most power. Some people prefer this method because they can check battery health at the same time.

When your iPhone turns on Low Power Mode automatically

By default, your iPhone will switch to Low Power Mode automatically when your battery drops to 20 percent. You will see a notification asking whether you want to enable it. If you tap "Enable", the yellow battery icon appears and Low Power Mode stays on until you manually turn it off or until you plug in to charge.

At 10 percent battery, your iPhone will turn on Low Power Mode again if it is not already on, and this time you cannot decline — the phone does it automatically. This second trigger is a safety measure to keep your phone from shutting down unexpectedly when the battery is nearly empty.

You can change when the first automatic trigger happens by going to Settings > Battery > Low Power Mode and adjusting the threshold, though most people leave it at 20 percent.

Why you might see yellow battery even when plugged in

If your iPhone shows a yellow battery icon while it is charging, Low Power Mode is still on. Plugging in does not automatically turn off Low Power Mode — you have to do that manually. This is intentional: some people leave Low Power Mode on even while charging because they prefer the slower performance or want to preserve battery health over time.

If you want your phone to return to normal speed while charging, swipe into Control Centre and tap the battery icon again to turn Low Power Mode off. The yellow will disappear and your phone will return to full performance.

The difference between yellow battery and red battery

A yellow battery icon means Low Power Mode is on — a setting you control. A red battery icon means your battery is critically low, usually below 5 percent, and your phone may shut down soon. Red is a warning; yellow is a status indicator.

If you see red, plug in when ready. If you see yellow, your phone is fine — it is just running in a power-saving state. You can keep using it normally, though it will be slower, or you can turn Low Power Mode off if you prefer speed over battery life.

Frequently Asked Questions

Does Low Power Mode damage my battery?

No. Low Power Mode actually reduces stress on your battery by lowering the processor speed and limiting background activity. Using Low Power Mode regularly may help your battery stay healthier over time because it generates less heat and uses less power.

Will my apps work normally in Low Power Mode?

Most apps work fine, but some may be slower to open or respond. Apps that rely on background refresh, like email or weather, will update less frequently. Games and video apps may perform noticeably slower. Once you turn Low Power Mode off, everything returns to normal speed.

Can I use Low Power Mode all the time?

Yes, you can leave it on permanently if you want. Some people do this to extend battery life throughout the day. The trade-off is that your phone will feel slower. You can turn it off whenever you want, even if your battery is at 100 percent.

Why did Low Power Mode turn on by itself?

Your iPhone automatically enables Low Power Mode at 20 percent battery by default. If you do not want this to happen, go to Settings > Battery > Low Power Mode and turn off the automatic trigger. You can still turn it on manually whenever you choose.