Many hams add power hungry radios to their vehicle power systems. A preferred way to obtain the power is directly from the battery terminals.
I have been adding various gadgets to my Ford Taurus to bring battery power into my passenger area so I can get rid of my cigarette lighter plug for my 2m/440 radio.
Adding a wire to my original battery posts was a problem so I used replacement posts from the car audio market. This turned out to be a mistake.
The original equipment battery posts on my car were the molded type which left no room to add any terminal or lug to the tightening hardware. So I turned to the Hi-Fi car audio market to see how the massive power needs of the “booming” stereos are met. All I found were fine looking chrome products. I really did not care about the chrome, but the terminal did have multiple holes for four wires: two large and two small. It looks like this…
Nice features include a way to attach your large gauge starter cable, the car’s power cable and your additional power cable for your extra equipment. Unfortunately, my Taurus’ starter cable is small and won’t fill even the smaller socket. I stuffed the car’s negative starter cable and power system ground into one of the smaller holes. Since I was not quite ready to install the rest of my power system, I left the positive terminal stock.
Then the big 2010 snow in Northern Virginia occurred. The house power went out so I retrieved the battery from my Taurus to run my 12 Vdc backup sump pump. This worked great. However, when I put the battery back into the Taurus and tightened the Allen screw to snug up to the negative post, the mechanism inside the Scosche terminal broke. Off to the auto parts store I went.
The only battery terminals available at this particular auto parts store were the simple lead clamp style. I purchased two installing one on the negative lead. This terminal has only one place to clamp wires. I decided to put not only the starter wire and the electrical system wire, but also my negative transceiver power wire into this clamp. I was worried about just shoving all three wires into this clamp, but, in the end, I got it in. After tightening, all three wires feel very secure. The car started with no issues suggesting this method is working for now. Here is a picture of the new terminal with all three wires…
No this isn’t much to look at, but makes the point this simple $1.25 post works just as well or, in my case, even better than the fancy chrome terminal. Don’t get me wrong, if you are pimping your ride, these chrome terminals look great, but I am trying to pimp my power.
This figure reveals the old and new posts along with the broken piece.
That extra sleeve sitting on the battery handle near the broken piece came with the chrome post adapter and was needed to make it work on the negative terminal. Yes, the negative terminal is the larger of the two posts on batteries so I don’t know why I needed the sleeve, but I did.
Conclusion
I was confident the Automotive HiFi accessories would provide benefits to the ham community with their similar peak current electrical environment. A post with multiple output ports seemed like just the thing for grabbing additional power straight from the battery terminals. In practice, it turns out to be not a good fit… at least for my Ford Taurus. The Ford’s wires were too small to take advantage of the large wire holes. The chrome post adapter easily broke with routine use. In the end, a good old lead terminal worked just fine even with three wires stuffed into it. I will check this terminal’s wire clamp often to be sure of its longevity.
I think I can now replace the positive terminal with confidence the $1.25 terminal works better than the chrome model.
Well, the best battery posts are made from lead. Lead is the best material because is very "plastic" and make a good contact not to mention is broke-resistant. Also, there is no electrocorrosion on the large surface between battery and posts.