How to check whether your remote's batteries are dead when it stops working.

Tech Newbee

How to check whether your remote's batteries are dead when it stops working.

Your smartphone's camera is indeed sensitive to IR radiation and if you want to try it for yourself, just use a common IR remote control. When a button is pressed, the infrared beam emitted from it will show as white or purple light in the viewfinder of your camera app. You can also use this trick to check if a remote control's batteries are dead or when it is going to exhaust them.