Laptops, and some desktops, have useful light indicators that signal when the battery needs to be charged or is charging, the read/write instances of the hard disk, the state of the Caps key, the camera on/off light, and more. These indicators, and what they do, are programmed so that an average user cannot change them easily.
Dell laptops, especially the newer models, all have a battery charge indicator. It indicates two things; when you connect the power adapter to the laptop, it lights up briefly to indicate that it is receiving current, and when your battery is charging the indicator remains on until charging completes. This is its default function and if you suddenly see the Dell battery indicator blinking, you might panic thinking there’s an electricity surge, something is wrong with the power adapter, or perhaps your battery is dying. That is not the case.
Fix Dell battery indicator blinking
The ‘fix’ for this is really easy. Execute the following keyboard shortcut on your system and the battery indicator will only light up when it’s supposed to.
If you’re using a Bluetooth/wireless/USB keyboard with your Dell laptop, it’s a good idea to use the built-in keyboard to run the shortcut. It’s possible that it may not work with an external keyboard.
Why this works
The battery indicator is known as the battery indicator because that is its default function. It has a secondary function that you can switch to by tapping the above keyboard shortcut. If your battery indicator suddenly began blinking, it is highly likely you accidentally executed the Fn+H keyboard shortcut causing it to switch over to its secondary function.
The secondary function of the battery indicator is to indicate read/write activity for the hard drive or the SSD.
The point is, the blinking light doesn’t mean anything is wrong with your system. It has nothing to do with an electrical surge or with your battery failing/dying. Once you know what this behavior means, you can opt to switch to it if you find it to be more useful. If you plug your laptop in to charge while it’s off, the light will still indicate that the battery is charging. It’s only when your system is turned on will the light switch to its secondary behavior.
This behavior has been observed on newer/recent Dell laptops. There is no official list available on which models support it and Dell hasn’t documented this feature much so you’ll only find out about it when it starts blinking constantly.