Laptop battery warning light no longer lights up?

I have the following problem. When my laptop battery runs out, the red lamp is lit. But not lately. Then at some point he just makes himself out. It's frustrating. Can you fix that.

Back up all your data and do a hard reset. The easiest and fastest way.

Before you do any resets or anything:

I'm not familiar with laptops, it can be that the lamp is burned through

So she's still going. It was a while that she didn't go. Then she left a few times and now again not. And it still lights up when charging.