Alarm or notification when battery fully charged

My friend!
Thank you for your answer
But I am looking for app that may solve my issue

I understand what you are looking for. Doesn't everyone want an easy button? ( An "easy button" is techspeak for a user wanting the machine to do all of the thinking for them!).

The part that is tough here is, you failed to mention the environment type, Apple or android! Try this link:
https://lmgtfy.app/?q=full+battery+app

There is plenty of apps in the store! Have Fun my friend!

I know my friend , you are totally right , but as i told you before , it's easy to get app making the take off the plug since we for example hear the notification alarm or see a pop out message , it's let's us preserve laptop battery more than we expect.

Anyway , i am using Windows 8.1.

YOu are mistaken sir. The PC can work on AC POWER its entire lifetime! 8.1 does not play well with ANYTHING, which is why Microsoft ABANDONED that OS and released 10 so quickly! There is no APP, for what you are wanting, as APPS are not part of the 8.1 environment. You are looking for software, and the last thing you want to do is INSTALL FREE software to help you control your battery. You will be giving up alot more than control to your battery, and will not be happy with the BLOATWARE SPYING on your battery! (Among other things!)

When I google windows 8.1 BATTERY notification, it displays a Microsoft store that has MOBILE apps, for mobile phones! DO NOT WORRY ABOUT a FULL CHARGE ON YOUR LAPTOP!

You run into issues when your battery is at 45%, and you put it back on the charger!!! That is what kills the battery! Keep it off until it reached less than 10%, then leave it on until 100%!!!!!!

You could SCHEDULE a TASK, that triggers (plays a sound) when the system log reports that the battery is FULL! Run through the system log, and find what event is fired when it happens, and build a trigger off that event!