Battery Cables

Ask a question...get an answer (or two).
Post Reply
falcon
Rough Carpentry Apprentice
Posts: 64
Joined: Fri Sep 29, 2006 10:58 am
Location: Sheridan, Wyoming

Battery Cables

Post by falcon »

Has anyone in this forum had any experience making up battery cables with welding cable instead of 2/0 marine cable? It sounds like it may be more flexible and easier to run and it may be cheaper.
Cheoy Lee Frisco Flyer "work in progress"
LazyGuy
Candidate for Boat-Obsession Medal
Posts: 349
Joined: Mon Jun 11, 2007 9:31 pm
Boat Name: Paper Moon
Boat Type: Luders 33 (Allied Boat Co.)
Location: Mystic CT

Re: Battery Cables

Post by LazyGuy »

Marine cable is difficult to work with because it is pre-tinned. I do not recommend using non-marine cable. Battery connections are probably the second most frequent source of fires on a boat after the stove. To use a cable not designed for the environment is asking for trouble. In fact, if you are not experienced in doing the crimp connections, I would recommended paying the extra money for the pre-made up cables.
Cheers

Dennis
Luders 33 "Paper Moon" Hull No 16

Life is too short to own an ugly boat.
falcon
Rough Carpentry Apprentice
Posts: 64
Joined: Fri Sep 29, 2006 10:58 am
Location: Sheridan, Wyoming

Re: Battery Cables

Post by falcon »

Thanks Dennis this is just what I needed to know. Speaking of electrical fires, I plan to run both the house and start battery lines through a fuse blocks located close to each battery. Question: what size fuse would you recommend? The longest run, the one going to the stater solenoid, could be about 12 feet.
Thanks,
Pete
Cheoy Lee Frisco Flyer "work in progress"
LazyGuy
Candidate for Boat-Obsession Medal
Posts: 349
Joined: Mon Jun 11, 2007 9:31 pm
Boat Name: Paper Moon
Boat Type: Luders 33 (Allied Boat Co.)
Location: Mystic CT

Re: Battery Cables

Post by LazyGuy »

Fuses are to protect the cable. Not the source or the load. So the fuse should match the ampacity of the cable. The ampacity is based on size of the cable and the jacket/insulation. The most conservative number I could find for 2/0 cable in the engine compartment for insulation rated at 60 Degrees C was 130 amps. It ranged, based on insulation, from 130 amps to (believe it or not..) 370 amps for 2/0 cable with insulation rated at 200 Degrees C. I am going to guess that you will buy quality cable which would be 90 Deg C cable which is rated at 233.7 amps. So I would go with a 200 Amp fuse (or smaller).

All of the reference information in this post came from "Boatowners Illustrated Handbook of Wiring" By Charlie Wing. If you are doing a lot of wiring work, it is a great reference. Also anything by Nigel Calder for wiring or anything else related to owning a sailboat.

For cable prices, check out bestboatwire.com
Cheers

Dennis
Luders 33 "Paper Moon" Hull No 16

Life is too short to own an ugly boat.
Maine Sail
Skilled Systems Installer
Posts: 243
Joined: Fri Feb 24, 2006 10:47 am
Location: Casco Bay
Contact:

Re: Battery Cables

Post by Maine Sail »

falcon wrote:Has anyone in this forum had any experience making up battery cables with welding cable instead of 2/0 marine cable? It sounds like it may be more flexible and easier to run and it may be cheaper.
The wire in welding cable is fine and flexible and very similar to UL1426 marine stranding. The jacket however does not meet ABYC E-11 electrical standards. It is also most often of a significantly lower jacket temp rating than the 105C of UL1426 marine wire. Heck much of it you buy on-line has no UL rating or jacket temp rating what so ever..

I have removed lots of welding cable from boats such as Sabre & other builders whi usedit in the 70's & 80's., where it has literally softened to the point of voiding due to engine oils etc... It is also usually black and corroded along its entire length under the jacket.....

For making your own cables this will help:
http://www.pbase.com/mainecruising/battery_cables

Also for battery cable fusing feel free to read this, it may help:

Battery Fuse Sizing - How To
http://forums.sbo.sailboatowners.com/sh ... p?t=130775

For battery cables on boats I would urge you to consider a UL1426 marine battery cable..

Here is the ABYC ampacity table for non-bundled wires. If using a "marine wire" such as Berkshire, Pacer, Ancor, Cobra etc.etc. they are usually 105C rated..

Image
-Maine Sail

Canadian Sailcraft 36T
Casco Bay, ME
http://www.marinehowto.com
falcon
Rough Carpentry Apprentice
Posts: 64
Joined: Fri Sep 29, 2006 10:58 am
Location: Sheridan, Wyoming

Re: Battery Cables

Post by falcon »

Thanks Dennis this helps a lot. I suppose that its best to use 2/0 cable size even though its a bear to work with. I don't have a lot of room and the batteries are located forward under the v-berth. The longest runs are the ground from the battery to the engine block at approximately 14 feet and from the battery switch to the starter solenoid at 11.5 feet.
Cheoy Lee Frisco Flyer "work in progress"
Maine Sail
Skilled Systems Installer
Posts: 243
Joined: Fri Feb 24, 2006 10:47 am
Location: Casco Bay
Contact:

Re: Battery Cables

Post by Maine Sail »

falcon wrote:Thanks Dennis this helps a lot. I suppose that its best to use 2/0 cable size even though its a bear to work with. I don't have a lot of room and the batteries are located forward under the v-berth. The longest runs are the ground from the battery to the engine block at approximately 14 feet and from the battery switch to the starter solenoid at 11.5 feet.
2/0 has little problem with flexibility.. I work with it almost daily...

This is 2/0 Berkshire....
Image


It will make just about any bend you need it too.
Image

Plenty of twists & turns here:
Image
-Maine Sail

Canadian Sailcraft 36T
Casco Bay, ME
http://www.marinehowto.com
User avatar
earlylight
Candidate for Boat-Obsession Medal
Posts: 342
Joined: Fri Dec 19, 2008 7:15 pm
Boat Name: Early Light
Boat Type: 1982 Sabre 34 MK I
Location: MD
Contact:

Re: Battery Cables

Post by earlylight »

Maine Sail,
I really like those battery boxes in your second photo. Do they come with lids or covers? Where can they be purchased? Thanks in advance for any info you are able to provide.
Dick Coerse
Early Light
Sabre 34 MK1
Solomons MD

http://earlylight160.net76.net
Post Reply