Imagine a self-powering electric car.....yikes!....can't have that!
Or self powering batteries....whoa!....no way.
What?....death rays(EM rays or Venus ECCM Technique).
Be careful if your a good inventor.
Check out this article: LINK
It's not possible. You can't charge a battery with current pulled from that same battery, the same way you can't power a water splitting device with the gases produced from the water that device has split. This is not up for debate, it's been proven over and over and over again. It's known as the second law of thermodynamics. I don't normally use wikipedia as a source, but the information seems pretty accurate on this page: Perpetual motion - Wikipedia, the free encyclopedia