Have you just suddenly noticed that the battery icon in the top right corner of your iPhone screen is now yellow? Usually it's white or green, or even red if you're on low battery, but right now it's yellow. Why is that? The answer is actually pretty simple. Your iPhone battery icon is yellow because Low Power Mode is currently enabled. If your battery icon is yellow, it does not mean that there is anything wrong with your iPhone battery.
Lower Power Mode is a setting on all iPhones running iOS 10 or newer. Low Power Mode can be enabled at any time by navigating to Settings > Battery, and toggling Low Power Mode to on. If you didn't do this, but your iPhone battery icon is yellow, what likely happened is that you turned it on by accident. If the battery level on your iPhone reaches 20% or lower, a prompt will display on your iPhone asking you if you want to switch to Low Power Mode. So if your battery is yellow and you didn't go to Settings to turn on Low Power Mode, chances are you probably tapped on the prompt inadvertently.
If you want to turn off Low Power Mode, you can navigate back to Settings > Battery, and toggle Low Power Mode to off.
You can also add Low Power Mode to Control Center by navigating to Settings > Control Center > Customize Controls and then adding Low Power Mode to the Control Center. Once it's in your Control Center you can toggle Low Power Mode on or off with one tap.
