Extending battery cables

[andrewe251003]

Hi

I got my first RIB in February and having spent the first few trips getting used to the quayside gatherings whilst I demonstrate my amateurish launches and recoveries, I am now trying to sort out a couple of things that don't seem right.

When I got the RIB, the fuel tank was out on the deck and the battery was in the space under the jockey seat. As part of getting it serviced I had the battery cables replaced as they were shot. I now realise that I have been a total numbnuts and that the battery has its own high level compartment at the front of the console and I should have the tank under the seat. My nice new leads are now too short. I understand from a web trawl that extending the cables is frowned upon as the joints are prone to water ingress and corrosion. What's the view on here? It just feels a bit mad to buy new longer cables after having spent £100+ on new leads only 6 weeks ago. Is there a decent way of extending them?

Thanks in advance

[spartacus]

Don't patch in new cable onto an existing power cable, that's a recipe for electrical faults down the line. Use tinned cable, solder ends, heat shrink protective sleeve, etc. You might be able sell existing cable on Ebay to recover some money. That's my tuppence worth!

Earlier thread on exactly the same subject. http://www.rib.net/forum/f36/extendi...ble-24022.html

[Chris Caton]

you can use butt connectors, either solder or screw fitting types, then heat shrink or self amalgamating tape to seal the joints

VWP - battery terminals

[andrewe251003]

Cheers. Seems opinion is divided reading that old thread. No idea why I couldn't find it though as I did do a search.

I can see that replacement is ultimately the best fix but I like the idea of doing a good butt joint as it means that I can spend the cash on juice getting out this weekend rather than fixing something I probably should have thought of in the first place. I feel slightly better knowing that the joins will be high up inside the console and not too exposed.

[colcreate]

If you really need to extend your battery cables perhaps look at Anderson style battery cable connectors. These are designed for the job, available in different sizes, easy to use and maintain. Although they are not waterproof they are extremely durable. If you use them within a console environment I'm sure they will last you at least a season or until you can justify replacing with longer cables.

[andrewe251003]

Thanks. Will check these out too. It will only have to last this season and I'll see about getting them done over the winter.

[Downhilldai]

Andersen connectors are good for a quick, effective, removable, plug in extension, but for a permanent joint, I'd suggest an inline crimp connector with heatshrink.

[nugent]

Personally would never add to a battery cable,,

[colcreate]

Just read the old thread regarding joining battery cables and saw this:

Originally Posted by Nos4r2

The ONLY thing I'll say on solder V crimp is there's a reason it's illegal to solder connections on aircraft.

For the record:
Soldering was once an accepted method of connecting cables in aircraft, there was a standard written for it and training for it's correct implementation.

I'm long since removed from that industry but was surprised to learn that what was once considered best practice is now (6 years ago) considered illegal. Who, when and why?

Back to the OP - Andrewe251003 - if that's your dob get an adult to help you
I think we all agree here that joining battery cables in an often exposed marine environment like on a rib is not ideal.
However a quality joint can be made by crimping and soldering that will retain the electrical properties of the cable. Just remember that if anything this will potentially be the weakest link in the system. Insulating the joint and protecting it from the environment are critical, lack of flexibility in the joint can be an issue and regular inspection and maintenance of the joint is advisable.
We all cut our positive cable and install battery cut off switches so perhaps you could treat this problem in a similar manner.

Good luck!

[andrewe251003]

Wish it was my DOB! Sadly it's the date of my second marriage...

[beamishken]

nothing wrong with joining cables the problems arise when cables are joined badly

make a good job of it & it will be fine

company I work for supply diver operated dredgers which run 440v motors subsea if a cable gets damaged we cut it, crimp & solder then pot the repair & happily send the cable down to 200m for the divers to use that's 20 bar of pressure & life threatening voltage

I'm sure if we can do that you can do a suitable joint inside your console

as said previously crimp,solder & good insulation are the way to go

I wouldn't want to waste £100 worth of cables

[jyasaki]

Originally Posted by colcreate

Soldering was once an accepted method of connecting cables in aircraft, there was a standard written for it and training for it's correct implementation.

I'm long since removed from that industry but was surprised to learn that what was once considered best practice is now (6 years ago) considered illegal. Who, when and why?

Likely the same reason the ABYC (American Boat and Yacht Council?) has gone against it: Soldering creates a "hard" spot in the wiring that tends to focus any flex on the adjacent section of wire. Under vibration, those areas tend to fail.

Personally, I don't see a whole lot of difference between the hardening from soldering, or the hardening from crimping a connector on, but that's what they suggest.

jky

[colcreate]

ABYC standards only prohibit soldering as the sole means of making a connection, they don't however exclude the use of soldering a butt connector and suggest the use of 60%/40% solder alloy.

[andrewe251003]

Originally Posted by beamishken

nothing wrong with joining cables the problems arise when cables are joined badly



make a good job of it & it will be fine



company I work for supply diver operated dredgers which run 440v motors subsea if a cable gets damaged we cut it, crimp & solder then pot the repair & happily send the cable down to 200m for the divers to use that's 20 bar of pressure & life threatening voltage



I'm sure if we can do that you can do a suitable joint inside your console



as said previously crimp,solder & good insulation are the way to go



I wouldn't want to waste £100 worth of cables

Happily this is also the view of a local marine engineer. He is coming round to crimp, solder and heat shrink it next week. Reckons that since the existing cables are so new, done properly with the correct crimping tool, the joint will last as long as the cable, Happy Days.

[lc0021]

I've had a bad experience with well connected cables.

I guess Beamisken's solution for joining the cables is the best way to join cables - ie soldering the cables and potting the joints in resin - BUT - its not easy for an amateur to properly solder a joint on 16mm cable, and potting the joints in resin isn't difficult - it mightn't be obvious to an amateur what kit to buy, and where to buy it.

I'd say just bite the bullet and replace the cables with new cables of the right length - or even - a bit longer then the right length.

It'll probably save you from heartbreak with engine starting or cutting out problems down the road...

'Been there - bought the new starter'...

[Jon Tallis]

Nothing wrong with extending battery cables provided it's done properly:-
- Get an auto electrician to advise the cable size you need for the new length of run(longer run = bigger cable). If your existing cables aren't at least this big you'll need to replace.
- Assuming you have standard 'ring' terminals crimped (properly) into your existing cables, get new extensions made up with matching 'ring' terminals. Crimp them on properly using the correct tool.
- bolt the new sections onto the old using stainless bolts, having cleaned up both sides of the terminals to a shiny finish first. Cut the bolts flush with the nuts after tightening and file off any sharp edges.
- Fully insulate the joints with self-amalgamating tape or ideally better still adhesive heat-shrink tubing. Use a couple of layers to be sure.
- Secure the cables so the joints can't chafe against anything and definitely not against eachother.

[andrewe251003]

Had the cable extensions put in this week and took it for a bounce round the Calf of Man today. Checked them afterwards and it all seems nice and secure with no signs of flexing or chafing on the heat seal. Let's hope it stays that way.