Battery Cable Clamp Rusted
 

My parents go to Florida every winter and I check their house and car (2010 Mazda 5) from time to time to make sure everything is fine. I put the key into the ignition and there aren't any dash lights, so I am pretty sure the battery is frozen/dead. It's been a brutal winter in Philly.

The worst part is, after opening the hood and cleaning off some battery corosion, I can't get the terminal cables off the battery! The nut holding the cable clamp to the battery terminal is rusted.

I tried WD-40 and it didn't help. Any tips on a commerical lubricant that can work? Also, any advice on tools to help remove that rusted nut? I got a Craftsman socket set but I can't budge the nut.

Mix baking soda and water to clean the corrosion off. You might have to replace the post clamp,but a pair of channel locks or vice grips should get it off.

if it's a 2010, it's time for a new battery, so remove it however you must.

I cleaned the corrosion off first, that's when I discovered the rust. The 5 has been in the garage since Dec 1, so the corrosion left on the terminals must have rusted all the metal.

I know to remove the negative cable first, so that's how I found out it was rusted. I'm a bit leery of working on the battery without removing the neg cable first. Over cautious or I am justifed being extra careful?

I've had 2 explode on me over the years. Fortunately they blew the sides out and not into my face. I had a friend get hit in the face by one. They had to remove his eyes to get the acid out of him and his eyes. Yea, be careful.