Why is my battre drain if you put on charge

[Android Central Question]

How can change my mobile key board to the Google keyboard sytem

 

[B. Diddy]

Welcome to Android Central! Which phone? Did you mean to post a different question in the body of the post, compared to the thread title?

For the battery question -- are you plugging it into a wall outlet or a computer USB port? Are you actively using the phone while it's plugged in, and if so, are you using battery-intensive apps?

For the keyboard question, you first need to make sure Gboard is installed. Open the Play Store app and search for Gboard -- is there an "Install" button or an "Open" button? If Gboard is installed, go to Settings>Language & Input​, select Default Keyboard, and select Gboard.