Interconnects for battery to thruster

Sorry for what is hopefully an embarrassingly simple question for you:

I need to connect a waterproof battery to a waterproof thruster. I’d like to use those rubber pressure interconnects that force close under pressure. hydroseal RMC?

Ideally, I’d like to do the least work (risk of error) and have both the battery and the thruster directly connect to each other via this RMC. No soldering or manual waterproofing ideally.

Can you suggest some products keywords that will be compatible?

I only need a small 12v battery and a small 12v submersible thruster. It only needs to drag 4kg 3km, so a 1kg lithium battery or maybe lighter I expect to be be enough.

 

How do you intend to fuse the hot?

I’m a bit confused here. If you need a waterproof setup; you still need to wire it properly. So, some ‘manual’ effort is required.

Soldering on a boat is essentially not done on electrical connections and crimping os the standard.

 

Waterproof is not necessarily the same as submersible. Just about any non marine metal part that touches water or is enclosed in a slowly permeable cover might corrode. Regular wiring might have to be sealed away from Water contact , like what is done with troll motors. Generally, Water corrodes, and salt water (or even the Salt Air Vapors) corrodes absolutely. Battery size varies tremendously, depending on how fast the 4 kg/ 3 km needs to be dragged! Do you have one week or 1 hour to go the 3 km?

 

I don't know how you got on with this, but a basic diagram of what you want to achieve would help. There is incorrect information given above, as crimping is not marine standard, it is cheap, amateurish and overused. Solder everything possible and you won't have a long face.

 

The simple answer is you use a IP6K9K or MIL-ST- 810 512.5 rated connector.
The complicated answer is you tell us the specifics of the setup, because no immersion rated connector is worth anything if water can find a way elsewhere into the system.

 

ABYC specifies "mechanical connection" and not solder by itself. Solder introduces another element into the mix if there is some movement between the terminal and the wire. Over time the
wire can work harden and break.

 

My 40+ years experience in salt water environments is very different Barry. There is very very little fresh water boating here, and some coastal waters have very high salinity.

I have never seen a soldered wire break, but I have seen hundreds, if not thousands, of tinned and untinned copper wires corrode away to nothing, and lots of crimped only terminals fail due to corrosion. The proof for me was in longevity, where taking a few extra minutes and some solder burns reduced callbacks to zero over years of usage. It wasn't like I was spending extra time and money on no good purpose, unsoldered crimps regularly fail, crimped and soldered I never had a failure.

On work hardening, is not crimping more likely to initiate it than heating (which is used to soften work hardened copper)?

 

Helmut,
I supplied the North American ABYC standard reference as I did not agree with the "not a marine standard"
I do wonder what the European standards are. We had a 34 foot Silverton for 17 years and was about 15 years old when we bought it. The only time it got a reprieve and got out of salt water was
when the bottom needed a recoat, cutlass work and a bent prop shaft. I do not recall a single crimp failure.

In the bilge where the crimp can be wet, ie bilge pump wiring, heavy battery lug connections for example, I crimp then coat the connection with a product called Liquid Electric tape.
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From AI
yes, you can join aluminum to copper using specialized solders or brazing rods, but standard solder won't work well; you need specific fluxes to remove aluminum's tough oxide layer and must manage galvanic corrosion by coating the joint or using proper connectors for electrical applications. Common methods involve using products like Al-Cop braze or Super Alloy 1
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So when you solder, do you go through this process, and melting back the wires insulation due to the heat?
==============================

 

I am not aware of any situation requiring a copper to aluminium electrical connection, and have never tried to solder copper and aluminium. Choice of flux is important and I much prefer flux cored solder with non corrosive flux.

On you not having crimps fail, I guess it is a lot different under a sealed deck than in open fishing/whatever boat. Those guys often specify soldered joins at initial fitout.

When a crimped connection fails it often takes out the cable too, because by the time you work your way up that cable to find verdigris free copper it is too short, and thus another crimp (potential failure point) to lengthen it.

I have used the paint on insulation but generally went for heatshrink over a butt join, if sealing is critical I would put a smear sealant like silicone or polyurethane under it.

I have never worked under US standards and am surprised to see this recommendation, as it contradicts a lifetime worth of experience. I haven't dealt with a commercial boat requiring survey for years and will wander down and have a look what is being done.

I'm not trying to say that soldering was the norm, but it was considered superior, and I would have pros seeking me out because I took the care to do quality work. Over time and thanks to the excellent Weller gas kit it took me very little longer than crimping also.

My biggest issue with crimps is that due to how they are formed it is not terribly uncommon for wires to come out after the crimp felt good. Especially in cramped spaces where cables run, there is not room for the tool, two hands and a set of eye balls.

If you are melting insulation you need to check technique.

 

If you solder joints here in the US; you won’t get an insurance survey. Just a fee and told to correct it.

A crimped joint gets heat shrink tube and can also be liquid taped and never get salty.

 

@Boat Design Net Moderator

Please consider removing the post from Saturday at 1:32pm where the poster declares crimping is against marine standards and infers I posted incorrect information. Soldering is diametrically opposed to the ABYC.

If there were varying standards, i.e. ISO vs ABYC, then such debate is healthy. As presented, it is simply not such conversation.

I’d go so far as to say the poster can make his arguments, but he cannot do so while suggesting my comments are incorrect.

For the edification of readers of this forum; it is important we don’t provide misinformation. Someone reading this thread may believe the poster to be correct simply because he said I was not.

 

Best solution to bad information is well sourced good information... cite abyc and give a link. If we start down a path of deleting post for poor information the forum would be a ghost town within the week.

 

The ABYC relevant sections are 11.16.3.7
11.16.3.8

Solder is not allowed to be the only means of connection, except where it is on a fixed panel like a pcb.

I have no problem with people presenting an opinion, but when they refute my comment as incorrect; it is incumbent on them, not me, to disprove my statement. And in a public forum, the issue with unfair debate is readers may become confused.

I believe part of the problem lies with the fact the ABYC is copy protected, so the best I can offer is a citation for others to go and read.

But I assure folks; I am not “incorrect”.