Notification when the laptop battery is full?

I need some tool that will give me a pop-up notification when my laptop is fully charged?

Take a look at IFTTT. There's certainly a possibility.

What is IFTTT

I have Linux Mint with XFCE Desktop and there's a popup with it… So take the opportunity to switch to Linux

IFTTT is an online software with which you can create bots that perform tasks autonomously. IFTTT means "if this then that". In German, "if that, then that".

As an an example:

If: You get a call

Then: Your cell phone light comes on

I don't really find anything like that there

Okay, then try the following program: https://batterycare.net/en/index.html