Cleaning your battery terminals seems like a fairly simple venture, but can cause you major headaches if not done properly. The first thing we want to talk about is getting ready to serve as the battery terminals. In today’s cars, you have a lot of computers, radios with memory, and a security radio that will lock themselves out if you disconnect battery power cause it thinks they’re being stolen. So the first step I would do before I service or disconnect the battery is I would purchase one of these. Basically it’s a lighter type receptacle or a 12-volt source that you’ve seen that you plug your phone into and a nine-volt battery and this would plug into an outlet in your desk that is hot all the time with the key off.
In other words, it has voltage to it all the time. With the key off, it’s probably the one you use to keep your phone charged. You want to make sure that it is a constant power and you plug this in. What that does is keeps battery to the power to the memory on the radio as well as the memory of the computer. When you’re done, you don’t have problems with the computer. Being locked out of your radio and having to learn what the code is so that you can then get back on your radio. That’d be the first step. The second step is you’re dealing with a battery that has sulfuric acid in it. The reason you needed to clean to clean the terminals is over time as corrosion because of that sulfuric acid vapor, collect on their battery terminals cause corrosion and cause a connection issue which can cause you to have a no start.
This happens over a long period of time. What you want to do is monitor your battery terminals and make sure that build-up doesn’t get bad and headed off before it becomes bad. Since you’re dealing with acid, you want to always wear eye protection. When disconnecting the battery, the very first thing you want to do is disconnect the negative terminal, not the positive terminal. The negative terminal will be noted by the negative sign on the battery. Positive will be a plus sign. The reason you want to disconnect the negative battery terminal first is, if your wrench touches anywhere on the body of the car, it doesn’t shock you. You’re doing a positive first, then you would arc or cause a short and you could burn yourself as well as do damage to the car.
You always want to do negative terminal off the first negative terminal on last. In this case, we have an eight-millimeter wrench that we would loosen the negative battery terminal, we’ll give it a wiggle and they’d get off. You want to set that to the side and make sure you tuck it somewhere where it’s not going to flop back over and make contact while you’re working with something else.
You want to go in and then scrape the inside of the terminals to get a good clean surface area as well as on the battery itself. I use the side of a screwdriver and just scrape it all the way around to get new fresh metal. As I said, you could buy a tool, especially for that that has an inside and outside. When you cleaned the terminals and cleaned the terminals, you might have a side post battery. You want to make sure that you get both sides of that plate and just get them nice and clean. Whatever you use, whether it be a metal brush or a screwdriver or maybe a little knife or the tool. The object is to get the terminal surfaces clean, both inner and outer. A lot of places will sell a pad that goes underneath the terminals that you could that helps keep this from happening, keeps that connection good.