Moderated Discussion Areas
ContinuousWave: Small Boat Electrical
|Author||Topic: Battery Cable|
posted 12-25-2007 08:42 AM ET (US)
I am in the process of moving my batteries from the stern of my Outrage 20 Whaler Drive to under the console. [Give me your] thoughts on what guage wire I should use. [Should the wire gauge be] 1/0 or 2/0? Also [seeks] good sources for the wire or pre-made cable. I went into West Marine and was shocked to see the 2/0 was $15 per foot.
posted 12-25-2007 12:05 PM ET (US)
I bought 1/0 for my 20' Revenge W/T, and thought it was overkill, but that is my style. I bought 100 foot roll, damaged at one spot in the middle, off of E-bay for about $85.00 including shipping. Check out E-bay but mak esur eyou are getting marine grade. You don't have to increase the size too much as the most you are adding is about 15 feet. Check the size of the wire you have now, a size 1 wire might be big enough.........Jack
posted 12-25-2007 12:12 PM ET (US)
Both of these topics are well covered in the archives. This website has a fabulous search index which produces very good and very fast results when searching the achives. Try these:
Marine-Grade Wire: A Price Survey; Recommended Sources
My advice on selecting the proper wire size for the primary battery distribution circuit:
Check the installation manual for your engine. This typically contains advice on cable size.
When you increase the length of the cables between the voltage source and the load, you have to increase the size of the conductors in order to prevent too much voltage drop from occurring in the distribution wiring between source and load. In the case of a starter motor the current draw is very high, probably over 100-amperes, so the potential (to make a bad pun) is there for significant voltage drop in the conductor.
A good source of information on wire size is
Marinco Technical Support--How-To Guides
[Updated Link to new location--ANCOR keeps revising their website and breaking these links]
By the way, I have a boat with a Whaler Drive. I would be interested to know why you think it will be advantageous to move the batteries out of the stern compartment where Boston Whaler intended them to be located and to the console.
posted 12-25-2007 12:19 PM ET (US)
The very useful ANCOR wire calculator has been moved to a new URI. You can find it at
This ANCOR wire calculator will help you calculate the voltage drop in your system. If you plan to extend the original cables, you may have to use very large cables for the extension so that the total voltage drop is below the threshold needed. If you plan to replace all the cables, you probably can use a cable that is larger than the original but small than would be needed in just the extension.
posted 12-25-2007 12:31 PM ET (US)
Thanks for the advice. Jim the reasons for the move are several: I am adding a live well in the center opening in the transome deck. I want to move some weight forward to make up for the weight of the live well. I also think it will be easier to have the battery selector switch under the center console.
I welcome your thoughts.
posted 12-25-2007 01:04 PM ET (US)
I agree with bulldog on both parts, look on ebay for marine grade wire (do not buy crap), Go with the Over kill much large than you need. The farther the battery from the engine the more strain on the starter, you want large wire to carry the load, I rigged my whaler in the end 1984 ( got a 1985 new looper). I got #1 ga wire and still using them today same wire. Most important to do good connections, I use large copper terminal ends for the battery and engine connections. I melt the solder in the ends (with a hand held torch) and force the wire end in the connection. Then I use heat shrink to protect the connection, and then protect the heat shrink with a type of grease to keep away the corrosion/salt water. Trust me go larger...good luck
posted 12-25-2007 06:21 PM ET (US)
""I melt the solder in the ends (with a hand held torch) and force the wire end in the connection.""
I would opt to swage the connections are they're intended to do. Unless you're really good at soldering, there's a good chance that you'll have a cold joint and not so good conductivity. The other advantage to swaging is that the individual strands of wire will retain their flexibility and be less likely to break. After swaging, use adhesive lined heat shrink tubing to seal the lugs.
posted 12-25-2007 06:33 PM ET (US)
The greatest load for the battery is the starter of the motor. It makes sense to have the battery located as close as possible to the most important load, the motor.
posted 12-25-2007 09:42 PM ET (US)
Acseatsri You keep the torch on the terminal/lug (keeping the solder hot and fluid) then place the wire into the open end of the terminal/lug. With some flux in the mix the solder runs up the wire and contacts with the terminal/lug, remove the heat and let cool. Your battery should be held down tight, you should not have any movement at the ends. I have swage all of my other connections in the boat, then use solder, then use heat shrink, then grease. And like I said my battery wires are over 20 years old(through the tunnel on the 16 whaler) with no breaks, no problems, and still using them today....good luck
posted 12-25-2007 09:46 PM ET (US)
When you need the cable, check out this site. The battery cable in half the price of Ancor at West Marine but the same type and rating. It is great stuff. You wont be disappointed!
copy & paste link below to your browser:
posted 12-25-2007 11:30 PM ET (US)
These prices look the same as that eBay "merchant" and I bet the shipping and handling will be much less.
posted 10-24-2008 09:38 AM ET (US)
ANCOR moved many of the resources linked above. The new location for these resources can be found from
posted 10-24-2008 05:21 PM ET (US)
I have 4 AWG on my 18' Outrage with the batteries located in the console and it seems to be just fine.
posted 10-24-2008 05:48 PM ET (US)
Ask Len Simpson (an86carrera). He got his from me.
posted 11-01-2008 02:13 PM ET (US)
Been buying from this company for years.
Top of the line on everything I bought.
2/0 Ancor cable is $5 a foot.
posted 11-01-2008 02:42 PM ET (US)
Just sent Crabby his cables. Pacer Marine 2GA, tinned lugs both ends and heat shrunk with adhesive lined shrink sleeve. 15' each. $80 total.
posted 11-01-2008 03:38 PM ET (US)
BTW, where do you get it that you need 2/0? You got a bow thruster up front? 4GA would be plenty, 2GA overkill, but nice to have.
posted 11-02-2008 09:46 AM ET (US)
Another source for technical information regarding wire size, current capacity, and voltage drop is from GenuineDealz:
As I have mentioned previously in this discussion and elsewhere, I have purchased small amounts of marine wire from GenuineDealz. I found the price to be low, the ordering very simple via their on-line purchase website, the delivery to be timely, and the quality of the wire to be excellent.
posted 11-03-2008 10:01 PM ET (US)
The cables that Seabob4 sent to me were very nicely made with the ends crimped and sealed. There is no good way to make these yourself. I chose not to and I have more technical resources than most people.
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