Military Battery Terminals- Questions

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Tin Man

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I am going to use marine terminals over the large posts on my Group 27 starting wet cell marine battery....thus avoiding the use of the built-in threaded post (not a strong connection).


I found these Military terminals and they look really good.... they are low profile (reduce overall heigh by approx. 1/2"-1" which I need) and you can connect your ring terminals on both sides of the bolt. Plus, the protective boots are large and cover nearly the entire post//threaded post.

https://www.amazon.com/dp/B01LLWKXV6...roduct_details



However, these Military terminals come with both bolts sized 3/8". These are where the ring terminal are connected. The 5/16" is used solely for tightening the clamp terminal to post.

The 3/8" ring terminal on positive starter cable from my motor fit great. I do not want to drill out or ream out my starter negative cable (5/16") to accommodate the 3/8" bolt, as my motor is new and do not want to chance any warranty issues for mods made to cable.


I was considering using a 5/16" bolt in place of the 3/8" bolt, would this work? Both nuts I am using are lock nuts.
The Amazon seller said NO to doing this...Quote, "The 5/16" bolt has too much room for movement and is prone to loosen. Additionally the amount of contact between the bolt and the terminal is greatly decreased which could lead to a buildup of heat in the terminal when drawing high amounts of current." Does this sound correct? It is on the negative side if that makes any difference.

IMG_6457.png

Thanks!


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Maybe insert a thin brass/copper 5/16'" ID sleeve/bushing into the bolt holes and then use 5/16" bolts.
If you have, or know someone who has a lead melting pot. you could probably fill the existing bolt holes with lead and redrill them to 5/16", there may be a better way, but those two come to mind.
 
Agree...I may go back to the standard marine clamps.
How do you cover the entire added marine terminal clamp and also the solo threaded battery post? Most covers only cover the marine clamp and its threaded post, but do not cover the threaded post of the battery.
 
That is a good question. There are a lot of covers for the fat terminals. Don't see them for the threaded posts. If your battery is in a covered box, then it should be OK.

Out of curiosity, before reading the OP, I was not aware there is an issue using the threaded terminals on a marine battery. Is it a concern with the wing nut coming loose compared to a hex nut?
 
The concern is that the threaded post is the "weak link" if you will. many times it is over tightened and can break off or cause internal damage (not always visible). Also, the heavier/thicker post is more stout and is preferred for the cranking amps needed for outboards. Threaded post can be used for lower amps....electronics, lights, etc. Hence, the use of added marine terminals that have an included threaded post....however this leaves the post unused and exposed...per ABYC battery terminals must be covered.

Locknuts are always used...just be sure to run the nut several times on a bolt before using it on battery so that is not putting undue stress on threaded post.
I believe wing nuts are not ABYC approved. ABYC is not federal law enforcement agency...but they rely heavily on USCG information, at least that it was I learned in USCG courses I took several decades ago.

I'll probably use the standard marine terminals and connect starter and charger cables to its threaded post The battery's internal threaded post I will use for my console power connection...which includes lights, graphs, live wells, etc.
 
The concern is that the threaded post is the "weak link" if you will. many times it is over tightened and can break off or cause internal damage (not always visible). Also, the heavier/thicker post is more stout and is preferred for the cranking amps needed for outboards. Threaded post can be used for lower amps....electronics, lights, etc. Hence, the use of added marine terminals that have an included threaded post....however this leaves the post unused and exposed...per ABYC battery terminals must be covered.

Locknuts are always used...just be sure to run the nut several times on a bolt before using it on battery so that is not putting undue stress on threaded post.
I believe wing nuts are not ABYC approved. ABYC is not federal law enforcement agency...but they rely heavily on USCG information, at least that it was I learned in USCG courses I took several decades ago.

I'll probably use the standard marine terminals and connect starter and charger cables to its threaded post The battery's internal threaded post I will use for my console power connection...which includes lights, graphs, live wells, etc.

This is good stuff, thanks. I'm using the terminal clamps as opposed to the posts -- that is the way the boat came rigged. Looks like I was doing the right thing without even knowing it.
 
That is VERY expensive for a battery terminal clamp. I wouldn't spend it, especially since you only end up with a regular bolt/ring connection. A properly cleaned, greased and tightened marine connection is the standard for a reason, and doesn't cost you an extra $25.
 
That is a good question. There are a lot of covers for the fat terminals. Don't see them for the threaded posts. If your battery is in a covered box, then it should be OK.

Out of curiosity, before reading the OP, I was not aware there is an issue using the threaded terminals on a marine battery. Is it a concern with the wing nut coming loose compared to a hex nut?
 
Reminds me a lot of the cheap replacement ends we'd buy at Kmart back when I was a teenager. I'm sure they'd work OK, but don't see any real inherent advantage to the design.
 
What! cheap replacement ends from the 70s lol.
The terminal covers fit snuggly and yes the did not break the bank.
 
I used rubber post covers on threaded post.

Shoot, I saw those and assumed they were for the big terminal lugs. Should have paid more attention to the size.

I'm going to be honest and say I have no idea if the threaded posts on my starter battery are covered or not. Next time I'm in the boat and think of it I'll open the box to see what is happening.

My TM battery uses the threaded posts. The lugs are covered with plastic caps.
 
My opinion, safer to start with the standards and go from there.
Fist pic - USCG boat builders guide.
Second pic - ABYC E-11 guidance on terminal protection.
 

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I used rubber post covers on threaded post.
Am I missing something....I don't see and ring terminals connected to the Military style clamps? I see the Blue Seas connectors that are connected to the threaded post, but nothing connected toMilitary clamps.
 
Am I missing something....I don't see and ring terminals connected to the Military style clamps? I see the Blue Seas connectors that are connected to the threaded post, but nothing connected toMilitary clamps.
 

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