Battery Terminals / Electrical Connections

I initially set out to replace the red accessory cable on this battery. The cable feeds a hose reel on a hydroseeder. There was a mishap, and the positive accessory lead from the battery got pinched between two steel plates and completely exposed the wire. I saw no signs of arcing, no burn marks on the steel, no melted insulation, so I thought all was OK after a quick inspection and cutting the cable to prevent a short until I could fix it.

You can see the terminal looks a little distorted, but I thought someone used a hammer to "tap" the terminal on at one time. (NEVER USE A HAMMER, you will likely crack the top of the battery around the post). I had a new cable to run, and figured I'd replace the nut with a stainless one. I removed the nut, and here is what I found.

At first glance, I thought corrosion had eaten away the terminal, and the ring terminal, which seemed odd, since the battery terminal was corrosion-free as you can see in the first picture. Looking closely, you can see the cable terminal actually melted the battery terminal! So although I saw no signs of shorting where the cable was pinched, it was shorting out, and the heat generated was enough to begin melting the lead battery terminal. If you look closely, you can see the melted drip of lead on the bottom of the terminal.

With the terminal removed from the battery you can easily see the melted drip. You can also see the distortion on the left side of the terminal in the picture.

This tool is a brush used for cleaning "top mount" or "post mount" battery terminal connections. The "hole" on the left side is for the battery post, and the brush on the other end is for cleaning the cable terminal.

Ready to clean the battery terminal.

You put the tool onto the post with a twisting motion. Three or four twists, then "unscrew" the brush from the post.

The result is a nice, clean post.

I am only using the melted terminal to demonstrate how the brush is used to clean the connection. A few twists with a screwing motion cleans the terminal nicely.

Before installing the new cable, I applied dielectric grease to the post, to help improve the connection, and help prevent future corrosion. I also use this grease on all bulbs, trailer plugs, and just about any electrical connections I make.

I was also wiring up some marker lights while I had all the wiring supplies out. I put dielectric grease on the end of the wire before I inserted it into the butt connector and crimped it. I then slipped a piece of heat shrink tubing onto the wire. I put the grease on the other wire, and inserted it into the connector, and crimped it. Then slipped the heat shrink tubing onto the connector and applied heat. I use a small propane torch, but some brands or types of tubing will even shrink with heat from a cigarette lighter.

Here it is, the connection is sealed, and protected from the elements.

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