welding cable as battery leads?

DonMacN · 04 May 2010, 11:10

Folks,

Haven't posted for a while since i got the boat up & running, but wonder if you wouldn't mind helping out?

It a 2008 model HondaBF90, supplied with the seemingly standard fit 'ridiculously short' power cables. I've had issues with join between these and the 'extensions' I had made up and now want to fit complete cables from battery to motor. As it's a dive RIB there's often a lot of water sloshing about the deck and cable joins just can't be a good idea - never going to know when they'll cause a problem.

My question is what rating cable do I need - the 'extensions' I had made up are from 35mm2 cable, but they're just a little bit too 'chunky' to fit easily into the grommet/gland that enters the cowling - though they will work at a push.

The OE cable is labelled AV20, but I can't find any spec for that. My dealer's been in touch with Honda UK, who apparently need to phone Japan to ask....!

I'm guessing the main draw is the starter motor, but does anyone have any good info on all of this?

My dealer is also raising the issue of the 'waterproofness' of welding cable. I'm assuming it's OK for a dive RIB application?

Any advice appreciated.

Cheers

D

BruceB · 04 May 2010, 11:52

Well I have used it for some years and had no problems. As long as both ends are well tinned and sealed (and not lying in any water) then I can't see how they would be any real problem, if water can't be drawn in then it can't rot the copper.
Certainly the difference in cost is such that even if I had to replace it every few years (and I haven't) it would still be worth using it due to the cost difference............

DonMacN · 04 May 2010, 12:23

Cheers Bruce,

THat's what I thought myself, but the dealer just put a doubt in my mind. It seemed to me that, quite apart from water getting in, the real danger in a work situation might be current leaking out, so the cable must be made to a decent spec.

Seems there's single insulated and double insulated stuff - are you just using the 'single' stuff?

Price up here for 35mm2 is somewhere around £4/m.

Hopefully some other kind soul can answer the question about cable rating.

Ta

D

Erin · 04 May 2010, 12:55

The cable size will depend upon the length of run. I believe 25mm would be adequate on most boats for that engine, but if you can go 35 it'll certainly not harm.

DonMacN · 04 May 2010, 13:04

I knew I'd leave out some important information! The cables I've just taken of are 5.4m long.

jwalker · 04 May 2010, 13:06

Go for the biggest diameter you can get through the grommets because that'll give you the lowest voltage drop. Welding cable is good. The strands are often tinned which will help prevent corrosion should you be unlucky and get water into them and the strands are small diameter too which gives the cable very good flexibility, unlike some starter motor cable. The outer is tough and heat resistant and can take a fair amount of abuse. Other cables I've used are heavy duty jump start cables, usually not tinned though but have the advantage one is black and the other is red if that matters to you. They too are flexible so easy to route and reroute if necessary.

Downhilldai · 04 May 2010, 13:11

Quote:

Originally Posted by jwalker

Other cables I've used are heavy duty jump start cables,

I've got some of them

I made them out of welding cable.

jwalker · 04 May 2010, 13:13

Quote:

Originally Posted by Downhilldai

I've got some of them

I made them out of welding cable.

Ah, but are they pretty coloured red and black like mine.

Downhilldai · 04 May 2010, 13:17

Quote:

Originally Posted by jwalker

Ah, but are they pretty coloured red and black like mine.

Yes, of course.

Well, the bits of insulating tape on the clips are anyway.

BruceB · 04 May 2010, 15:13

I am sure I have red and black welding cable, if pushed I can check through the boat file and find out where I got it as I will still have the receipt in there somewhere.
Its fine stranded and flexible but I don't remember it being tinned. 35mm if I remember right.

Rogue Wave · 04 May 2010, 15:28

i've used welding cables for years no probs. don't forge they are tinned unlike most of te ones supplied by dealers.

Re the dealer putting doubt in your mind about something you weren't sourcing from him I was under the impression that was his Job!

DonMacN · 04 May 2010, 19:56

thanks for all the replies folks. The cable I priced earlier definitely wasn't tinned, so maybe need to think about that.

Quote:

Originally Posted by Rogue Wave

Re the dealer putting doubt in your mind about something you weren't sourcing from him I was under the impression that was his Job!

Indeed! but to be honest it was the servicing guy rather than the salesman, and I probably would have bought a pukka set of longer Honda leads if they made them, but they don't.

These days it's an £8500 engine RRP, and it only comes with 2m power cables! They don't even offer longer versions, and for an engine that's clearly designed to be remotely started/operated, it just doesn't seem to make much sense to me. I can only assume that RIBS, shipping lots of water etc, aren't the target market for them?

As I say though, ta for all replies.

Erin · 04 May 2010, 20:10

Quote:

Originally Posted by DonMacN

I probably would have bought a pukka set of longer Honda leads if they made them, but they don't.

These days it's an £8500 engine RRP, and it only comes with 2m power cables!

And if they're anything like Suzuki, they won't even be tinned. How can a manufacturer boast about making a quality marine item and then supply it with standard copper cable.

martini · 04 May 2010, 23:18

I get all my marine cable from http://shop.genuinedealz.com/
Never had any problems with them re shipping etc, it's all the highest quality stuff. There's also tables on the site for calculating wire sizes etc and prices are pretty good too

edit: Just noticed Cookee's a fan of the facebook page so there's another recommend!

Erin · 05 May 2010, 08:29

Quote:

Originally Posted by martini

I get all my marine cable from http://shop.genuinedealz.com/

Yep, I bpught all my stuff from them too. However, I think the exchange rate was a little better at the time than it is now!

jyasaki · 05 May 2010, 15:45

Quote:

Originally Posted by DonMacN

thanks for all the replies folks. The cable I priced earlier definitely wasn't tinned, so maybe need to think about that.

Seal up any place you've exposed the conductors (using adhesive lined shrink tubing, liquid electrical tape, hot glue gun or whatever), inspect the seal fairly often to prevent seawater ingress, and plan on replacing them after a few years.

jky

Nasher · 05 May 2010, 19:29

Quote:

Originally Posted by jyasaki

Seal up any place you've exposed the conductors (using adhesive lined shrink tubing, liquid electrical tape, hot glue gun or whatever), inspect the seal fairly often to prevent seawater ingress, and plan on replacing them after a few years.

jky

What jky said

Welding cable works a treat with the above precaution, I use adhesive lined heat shrink, and can be picked up really cheap.

Nasher