This is the Reason Why Kakashi Never Use Rasengan

This is the Reason Why Kakashi Never Use Rasengan
Naruto.Wikia.com
Kakashi Hatake is the greatest disciple of Minato Namikaze, he is also the teacher of Naruto Uzumaki. So far we know Kakashi as one of the shinobi users of Chidori.

But actually Kakashi is also able to create Rasengan as well as Minato. With his Sharingan ability Kakashi is able to copy all the jutsu he has ever seen, including the Rasengan.

The Rasengan is a very powerful technique with A-Level, the technique invented by the Fourth Hokage, Minato Namikaze, which he created by observing the Beast-Monster Ball.

Then why kakashi never used rasengannya during the war?

Although the Rasengan created by Kakashi is the result of Copy but Kakashi can make Rasengan with ease, but for his ability Rasengan Kakashi is not as good as the real Rasengan.

Rasengan is not a wind element but the moment of chakra collection in one point.

Therefore Kakashi mentioned that rasengan requires too much chakra concentration so he never uses it.

Instead he created his own alternative, chidori, to suit him.