A yellow battery bar means Low Power Mode is on

Your iPhone's battery icon 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 runs before it needs charging. When Low Power Mode is on, your iPhone slows down some background activity, dims the screen slightly, and limits performance — all to stretch battery life.

Low Power Mode typically activates automatically when your battery drops to 20 percent, though you can turn it on manually at any battery level. The yellow color is Apple's way of telling you the phone is running in this reduced-power state. It is not a warning that something is wrong — it is a deliberate choice your phone made (or you made) to keep it running longer.

Key Takeaways

  • A yellow battery bar means Low Power Mode is active, which slows your phone's performance to save battery life.
  • Low Power Mode turns on automatically at 20 percent battery, but you can enable it manually whenever you want.
  • You can turn Low Power Mode off in Settings > Battery, or by tapping the battery icon in Control Center.
  • Low Power Mode does not damage your battery — it is a temporary setting that you can switch on and off as needed.
  • If the battery bar stays yellow even after you turn off Low Power Mode, your battery may need service.

How to turn off Low Power Mode

If you want your phone to run at full speed again, you can disable Low Power Mode in two ways. The fastest is to open Control Center (swipe down from the top right on newer iPhones, or swipe up from the bottom on older models) and tap the battery icon. It will turn gray, and Low Power Mode will turn off when ready.

The second way is to go to Settings > Battery, then toggle off the Low Power Mode switch. Both methods do the same thing — the Control Center route is just quicker if you are in a hurry. Once Low Power Mode is off, your battery icon will return to its normal color (red if the battery is low, black or white depending on your iPhone model).

Why your phone turned on Low Power Mode automatically

When your battery reaches 20 percent, iOS automatically enables Low Power Mode without asking. Apple designed it this way so your phone keeps running longer without you having to think about it. At 20 percent, you still have time to find a charger, but your battery is draining fast enough that the phone wants to buy you extra time.

You can disable this automatic behavior if you prefer. Go to Settings > Battery > Low Power Mode, and you will see an option to turn off automatic set up. If you do this, Low Power Mode will never turn on by itself — you would have to enable it manually whenever you want it. Most people leave the automatic setting on because it is genuinely useful when you are away from a charger.

What Low Power Mode actually does to your phone

Low Power Mode makes several changes to how your iPhone operates, all designed to use less power. It reduces the screen refresh rate, limits background app activity, disables some visual effects, and caps your phone's processing speed. Email and iCloud sync slow down, and some features like Hey Siri may not respond as quickly.

These changes are temporary and completely reversible. Turning off Low Power Mode restores your phone to normal operation when ready — nothing is permanently changed. Low Power Mode does not damage your battery or harm your phone in any way. It is straightforward a power-saving mode, like the ones found on laptops and tablets.

When the yellow bar stays on even after you disable Low Power Mode

If your battery icon remains yellow after you have turned off Low Power Mode in Settings and Control Center, restart your iPhone. Hold the power button and volume button together (or just the power button on older models) until the power-off slider appears, then slide to shut down. Wait a few seconds, then press the power button again to turn it back on.

If the battery bar is still yellow after a restart, the issue may be with your battery itself rather than the Low Power Mode setting. Your iPhone's battery degrades over time, and if it has lost significant capacity, your phone may display the yellow icon to indicate the battery needs service. You can check your battery health by going to Settings > Battery > Battery Health & Charging. If the maximum capacity is below 80 percent, Apple recommends having the battery serviced.

Difference between yellow battery and red battery

A yellow battery bar means Low Power Mode is on — your phone is intentionally running in a power-saving state. A red battery bar means your battery is critically low (usually below 20 percent) and your phone will shut down soon if you do not charge it. Red is a warning; yellow is a feature.

You can have both at the same time. If Low Power Mode is on and your battery drops very low, the icon will turn red while Low Power Mode is still active. The red color takes priority because it is the more urgent signal. Once you charge your phone above 20 percent, the icon will return to yellow (if Low Power Mode is still on) or to its normal color (if Low Power Mode is off).

Low Power Mode and charging speed

Low Power Mode does not affect how fast your phone charges. Whether Low Power Mode is on or off, your iPhone charges at the same speed when plugged in. However, Low Power Mode does reduce power consumption while you are using the phone, so if you use it while charging, your battery percentage will climb faster than it would if you were using the phone at full performance.

Some people leave Low Power Mode on while charging to speed up the process, though the difference is usually small. Once your battery reaches 80 percent, iOS automatically slows charging to protect long-term battery health — this happens regardless of Low Power Mode status.

Frequently Asked Questions

Does Low Power Mode damage my battery?

No. Low Power Mode is a temporary setting that reduces power use while your phone is running. It does not affect your battery's long-term health or lifespan. You can turn it on and off as many times as you want without any negative effects.

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

Yes, but it will be slower. Apps may take longer to open, animations will be less smooth, and some background tasks will pause. For most everyday tasks like texting, calling, and browsing, you will not notice much difference. Gaming and video editing will feel noticeably slower.

Why does my battery bar turn yellow at 20 percent instead of some other level?

Apple chose 20 percent as the threshold because it is low enough that you should find a charger soon, but high enough that you still have time to do so. At 20 percent, most iPhones have 1 to 2 hours of battery life remaining, depending on what you are doing.

Will Low Power Mode turn back on automatically after I charge my phone?

No. Once you turn off Low Power Mode, it stays off until your battery drops to 20 percent again (if you have automatic set up enabled) or until you manually turn it back on. Charging your phone does not re-enable it.

What if Low Power Mode is draining my battery faster than normal?

Low Power Mode should extend battery life, not drain it faster. If you notice the opposite, restart your phone. If the problem continues, check Settings > Battery > Battery Health & Charging to see if your battery is degraded. A battery below 80 percent capacity may behave unpredictably.