Each different color battery icon gives you useful information—if you know what it means. It’s important to understand what these icons mean and what you should do when you see them. In at least one case, it can save your iPhone from serious damage.
Red Battery Icon on iPhone: Time to Recharge
You’ll see a red battery icon on your iPhone if it’s been a while since you last charged your iPhone. When you see this, your iPhone is telling you that its battery is low and needs to be recharged. If your iPhone is showing the red battery icon in the top right corner, it needs a charge, but still has a enough power to work. It’s hard to know exactly how much life it has left (unless you’re viewing your battery life as a percentage, that is. We recommend it), so recharge your phone as soon as you can. If you’re not able to recharge right away, try Low Power Mode to squeeze more life out of your battery. More on that later in the article.
Red Battery Icon on Lock Screen: Very Low Charge
If you’re seeing the red battery icon on the iPhone lock screen, that means something slightly different than seeing it in the top right corner. When the red battery icon appears on the lock screen, that means your iPhone battery is so low that the phone can’t even turn on. Plug your iPhone into a power source right away to start charging the battery. After a few minutes, it will have enough power to turn on again. You’ll just see the red battery icon in the top right corner at this point.
Orange Battery Icon on iPhone: Low-Power Mode
Sometimes the battery icon in the top corner of the iPhone screen turns orange. (You won’t see this icon on the lock screen.) That color signals that your phone is in Low Power Mode. Low Power Mode is a feature of iOS 9 and up that stretches your battery life for an extra few hours (Apple says it adds up to three hours of use). It temporarily turns off unnecessary features and tweaks settings to squeeze as much life as possible out of your battery.
Green Battery Icon: iPhone — Charging
A green battery icon on your iPhone lock screen or in the top right corner is good news. It means your iPhone’s battery is charging. If you see the icon with a little lightning bolt next to it or in it, you know your iPhone is plugged into power.
Red Thermometer Icon: iPhone Is Too Hot
Seeing a red thermometer icon on your iPhone lock screen is uncommon—and it’s serious. The red thermometer can be a little scary since your iPhone won’t work while the thermometer is present. An onscreen message also tells you that the phone is too hot and that it needs to cool down before you can use it. This is a serious warning. It means that your phone’s internal temperature has risen so high that the hardware could be damaged (overheating has even been linked to cases of iPhones exploding). According to Apple, when the device overheats, the iPhone protects itself by turning off features that could cause problems. That includes stopping charging, dimming or turning off the screen, reducing the strength of wireless data connections, and disabling the camera flash. If you see the thermometer icon, immediately get your iPhone into a cooler environment (but not a freezer! Low temperatures can damage the phone, too). Then wait until it’s cooled down before you try restarting it. If you’ve tried these steps and let the phone cool for a long time but are still seeing the thermometer warning, you should contact Apple for support.
