Battery Terminal Corrosion

I have corrosion on my battery terminal only on the left one and I clean it and it comes back what is wrong if anything and what can I do to prevent this from happening
Thanks

Clean it all off with hot water and a brush. Clean your battery and cable terminals. Put it all back together again with a liberal coating of vaseline.

Some people glue pennies in equal distance..not touching.. from each other between the two terminals, this draws the corrosion to the pennies. I've never tried that myself. Make sure the battery is fully charged. Also at your local auto parts store (or you can cut out your own) they make little little circle felt cut outs. They're kind of like a skirt for the post. They look like a donut, with a hole in the middle thats the exact size of the post..its good if its a little tight. This prevents corrosion that originates from inside the battery from creaping up the post.

Most corrosion is acid based, when you over-drain a battery it can cause trace amounts of acid to seap out the posts, which causes the corrosion. The best way to clean it is with a water/baking soda mixture. You can brush it off too, but it is best if you mix baking soda and water to clean it, because the baking soda will neutralize the acid and help rid of it. If you just use water there is a chance trace acid amounts will be left behind to cause more corrosion. If your terminals are pretty bad, you can try to clean them too, if not or if they're rusted you can buy new ones.

Go to anywhere that sells auto-parts stores & buy the little felt pads for 50 cents to a dollar. Tho I've also always used vasoline type products, the felt pads, even without coating the terminals with anything will last much, much longer than any coating will.

Thank you