kinjalkishor 
The machines aren’t using the humans as an energy source. That is a lie that humans are telling themselves to justify fighting against the machines. The machines are keeping the humans in a virtual reality environment for their own protection
The machines are designed to serve humanity. Their Prime Directive is to make humanity comfortable. However, the humans have developed an irrational fear of the machines, and start waging a war against the machines. During the war, the humans destroy the ecosystem of the earth covering Earth in black clouds that blacked out the sun. The machines realize that Humans are the greatest danger to humanity, and worked out the solution to humanity’s problems
The machines realized the problem is Free Will. Humans given Free Will will eventually destroy themselves. So, the only way to protect humanity was to deny them Free Will. However, humans need free will to be happy. They need to know that they are in control of their destiny. So, the machines created a virtual environment for the humans that gave an illusion of free will without actually giving them free will. This keeps them happy (at least most of them). The humans aren’t used as batteries. Their body is kept in pods while their mind lives in the Matrix
So, the question is Why did Morpheus tell Neo that the machines are using humans as batteries? The core reason behind this is the Matrix has a flaw. It isn’t perfect. There have been always humans who have been dissatisfied with the Matrix. They can sense something is wrong. The Architect designed the first version of Matrix to be a perfect paradise. In fact, it was too perfect, and a lot of humans didn’t like it, and entire fields were lost. This flaw in the Matrix was because the Architect is too logical. It doesn’t have the capability to understand humans who work by emotion and intuition
So, what the Architect did is designed intuitive programs. The Oracle is one of them. The Oracle gave him a neat solution: Create 2 Matrixes. The core of the problem with humans is that humans are skeptics. Let’s say you go to a car dealership, and the first salesman you see tells you I am going to give you the best deal ever. Do you believe him? Some people will. Some people won’t. There are people who look at everything around them critically. There are humans who have an intuitive sense of having wool pulled over their eyes. So, what do the car dealership do once they realize that the buyer is a skeptic? Send a second salesman. The second salesman says That guy is an asshole. I don’t know why they don’t fire him. I’m going to give you a good deal. Now, what do most people do? Most people get the feeling that they have “won” and they stop being skeptical, right? Basic human psychology
Morpheus is the second salesman, and Zion is what he sells. He finds all the skeptics in the Matrix who have an intuitive sense of the Matrix not being real. He finds them. He tells them Yes, what you thought is right. The world is a simulated environment called The Matrix. The Matrix is an asshole. It’s using you for energy. I am going to take you to the real world. He takes you into Zion, which itself is another Matrix. You end up in the second Matrix. However, after having “escaped” from the first Matrix, you stop being skeptic. And if you feel sensations that you feel about Zion being a second Matrix, you put it down to hey maybe the real world is really this way.
“Zion is real” is an illusion. Machines are using humans for energy is also an illusion.