How to Avoid Sparking with Car Battery Terminals

Video Transcript

"Hi, I'm Aaron Gregory on behalf of Expert Village. And, we're going to talk about what happens when your car battery dies, how to select a new battery, and how to see what the problem is. So, the first step is we're going to see if the terminals are tight. Now, if you wiggle the terminals and they twist, sometimes that means there's enough of a gap between the terminal and the clamp that there's corrosion in there that you can't see. So, let's pull these terminals off and look inside there and see what it really looks like. So, we're going to remove these terminals with a wrench. This car is foreign, Japanese made, so I'm using a metric wrench. It happens to be a 13mm wrench. Now, the wrench is metal, and it's a very good conductor. The battery creates a lot of electricity between these two poles. As you can see, this wrench is long enough to contact between the two battery terminals which could result in a very powerful spark, and liquid lead or metal shooting off in those sparks. A good way to avoid causing sparks at the battery with your wrench is to begin by disconnecting the negative terminal first. That way, when your touching the terminal with your wrench, if the wrench touches any other part of the car, there's not going to be a difference in currant resulting in a spark. If you start with the positive terminal while the battery is connected and you touch the body of the car, you're going to arc twelve volts from the battery to the car because there's a difference in voltage. And, you're electrical system controls all that power. So, you want to be careful and if you're not experienced, maybe you should cover your wrench with electrical tape except for the very tip."