My IPad will only charge when I'm not on it?

My iPad is an iPad Air 2, hence the name, it is a 64GB gold and was brought on the twenty ninth of April, 2016 (this year). I do have two problems, my iPad is often used for complete work, and for entertainment. It has been treated very carefully. But when my iPad begins to die down, I can not charge it while I am on it. Although the charging signal is showing, it quickly goes flat while I am on it. But once turned off, the iPad will charge like normal. I have had the second normal iPad, but the screen cracked, and I never experience a charging problem like this. Another problem, is that my iPad keyboard goes all funny every once in a while, I will type a letter, and I will have to tap it a few more times before it actually shows up. Any help?