Is this a safe connector to 50 Ah lithium battery?

NickMDal

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Aug 12, 2013
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Hi. Getting to my question first, would some type of inline switch (between the fuse and positive post) make these nylon quick-release connectors reasonably safe?

This battery powers a (large kayak) Minn Kota trolling motor (un-shown clamps to hex head posts). It's firmly in hull.

This year I am adding a waterproof cigarette lighter power plug to the hull. It runs to the battery as shown. It is to power a 12v air pump for a small inflatable mat. The (battery - power plug - air pump) combo worked well when testing at home.

I spliced the new plug cable (as shown) and added nylon crimped connectors.

In the kayak, as I was connecting the black connectors, the red connector got near one of the posts and "pop." The 15 amp fuse burned out. Not sure if it arc'd or if the spade in the red actually touched the post.

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alldodge

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I don't see any issue with safety but do see a possible issue with use. You have two male connects of the same type and the only difference is the red tape. I would make one of them the female side connector. This way the leads will not accidently be swapped
 

NickMDal

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Thanks for helping! Okay so maybe just keep the connectors away from the terminals and mix the genders.

If I touch both posts at a time with my bare hands, some safety mechanism prevents shock. If I touch both spade connectors, is that protection still there?
 

Alumarine

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Thanks for helping! Okay so maybe just keep the connectors away from the terminals and mix the genders.

If I touch both posts at a time with my bare hands, some safety mechanism prevents shock. If I touch both spade connectors, is that protection still there?

The short answer is YOU don't get a shock because it's 12 volt dc.
There is no safety mechanism.
If you put a wire between the posts then you have trouble.

Here's an explanation, I didn't read much of it so I don't know how accurate it is.
https://www.lifewire.com/electrocuted-by-a-12-volt-car-battery-534763
 

alldodge

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Agree, short answer is your not going to get a shock from DC and this voltage level
 

NickMDal

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Wow this is completely interesting and helpful. I've always wondered if the voltage running through even the metal battery handle hinges were a hazard.

I do still have a basic question. I am a little confused about why the fuse blew. Is it likely that the positive crimp connector touched the negative terminal?
 

Silvertip

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That carry handle is a problem in that the metal hinges act as an extension of the battery post themselves. Any tool or conductive material you have in the boat that can contact those hinges creates a serious short circuit. You are confusing your body's conductivity with that of metal. Getting a shock and creating a short circuit are two entirely different things. Lose the carry strap. There are also high amperage connectors you can use with the trolling motor to eliminate the clamp type connectors on the trolling motor cables (which I assume you are using).
 

bheff

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If you are using the wire pictured as a pigtail to plug your trolling motor into, I would say that your wire gauge is too small.
 

NickMDal

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Aug 12, 2013
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image_277001.jpg

The wire shown is just for the air pump. The trolling motor wire is heavy and uses clamps.

Since the battery handle is unfortunately necessary, I taped over the exposed clips. Also added empty crimps with tethers to keep the crimp spades away from the posts and each other. Very helpful thread.
 
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