[ubuntu] Low battery warning on top of all windows

Hi,

Ubuntu v 16.04 LTS 64 bit

The low battery waing isn't on top of all windows and hence it is not showing when I play VLC or other in full screen. It is very important to show the low battery waing on top of all windows (even when you play in full screen). Low battery waing sound is coming, but that is not useful as a visual waing.

So how to make it on top of all windows?

Thanks.