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Author Topic:   Primary Battery Distribution Wiring on 19-footer
Austin Whaler posted 04-03-2009 06:23 PM ET (US)   Profile for Austin Whaler   Send Email to Austin Whaler  
I have just finished making a wiring diagram for my 19-foot Boston Whaler Outrage, and figured I would have a second opinion or hopefully more opinions on it.

[Gave a link to his wiring diagram, but later realized his diagram was incomplete or inaccurate.]

If anybody has any hints or tricks, tell me. I am 15 and this is the first full wiring job I've done.

Over the LINE posted 04-03-2009 07:45 PM ET (US)     Profile for Over the LINE  Send Email to Over the LINE     
Do you need a charger? If you are only running one battery I would hope not. You should not pull more power from your battery than your alternator can replace or you may find yourself stuck on the water.

Do you plan to install a main battery disconnect switch? On/Off switch? I would.

As for the size wire, the longer the run the larger it needs to be. I know there are discussions on here about wire size you could search for.

There are plenty of hints if you do a search about connection type, shrink tubing, etc. Here is a thread that includes what I did but there are many discussions to help you.

Austin Whaler posted 04-04-2009 09:12 AM ET (US)     Profile for Austin Whaler  Send Email to Austin Whaler     
[You] are right. [I] do not need a charger with one battery. [My] original sketch was a dual battery set up, and [I] forgot to take the charger out of the sketch. The other thing is [I] forgot to put in the On-Off switfch.

When I put the battery switch in, should it stop power from going to the motor or just the house load?

jimh posted 04-04-2009 09:43 AM ET (US)     Profile for jimh  Send Email to jimh     
Typically the battery primary disconnect switch will disconnect all loads from the battery, however there may be a very limited number of "keep alive" loads which remain connected to the battery even when the primary battery distribution switch is in the OFF position.

Examples of loads which remain connected to the battery even when the primary battery distribution switch is in the OFF position are:

--feed to a sump pump which is designed to operate automatically from a float switch or other sensor;

--feed from an AC-power operated battery charger which will charge the battery; although normally a source of power, there may be a miniscule current drain due to the reverse current flow through the diodes of the charger;

--feed to certain electronic loads which have a separate power input intended to maintain stored data.

As soon as you revise your wiring diagram to incorporate the changes you describe, we can offer further advice. It is almost impossible to describe electrical wiring in a narrative form, so it will be necessary for you to revise your drawing so that we can appreciate your actual wiring intentions.

Austin Whaler posted 04-04-2009 09:57 AM ET (US)     Profile for Austin Whaler  Send Email to Austin Whaler
Austin Whaler posted 04-04-2009 10:04 AM ET (US)     Profile for Austin Whaler  Send Email to Austin Whaler     
I thought to use [8-AWG] wire to go from the battery to the console originally, but, without the charger, is it still needed? Now [I] am thinking 10 guage but i am not sure. I will most likely be running a charger to a handheld GPS, a fixed mount VHF, deck lights, a small spotlight, and possibly a stereo with 2-4 speakers in the future.
jimh posted 04-04-2009 10:43 AM ET (US)     Profile for jimh  Send Email to jimh     
To select the proper wire size in your primary battery distribution wiring, you have to consider three factors:

--the maximum current load on the circuit branch;

--the maximum voltage drop that can be tolerated;

--the minimum wire size required or recommended by federal regulations or by boating standards organizations

If the three requirements conflict, you use wire of the largest wire size required.

In the case of the feed from your battery to a secondary distribution panel for house loads, you need to inform us of the total current load you anticipate.

Over the LINE posted 04-04-2009 06:57 PM ET (US)     Profile for Over the LINE  Send Email to Over the LINE     
From your diagram, I would suggect that the battery switch also disconnect the engine. As Jim said above, it is common practice for the ON/OFF to disconnect power to almost all circuits. The only thing I commonly wire directly to the battery is a bilge pump. On the job I linked above, there is nothing wired directly to the battery.

As for wire size, I have to admit I am pretty lazy when it comes to calculating needs. I often just oversize and call it a day. Unless you are talking about primary battery cable, the cost to upsize is usually not bad. I think my fuse panel is fed with 10ga but if you notice it is a distance of less than a foot.

You mention flood and spot lights. Both can be big power draws. Also the stereo, if you start pushing amps and big speakers, can be a significant draw. I would follow Jim's advice and do a needs analysis and distance calculation. Remeber that you are measuring the actual wire length not just the distance in a straight line.

Austin Whaler posted 04-04-2009 08:41 PM ET (US)     Profile for Austin Whaler  Send Email to Austin Whaler     
I went to my local west marine and asked them they said that the 10 AWG would be sufficient. While i would usually just over do it also the difference in price is $1/ft. When i say spot light i mean the kind that you plug into a 12 socket. The stereo isn't even close to happening yet as its not in the budget (aka all the money i have). When i do get one it will be the regular old deck and 2-4 regular speakers nothing fancy, no amps etc. My run is only 6.5 ft so there shouldn't be a high loss of voltage.
Newtauk1 posted 04-05-2009 10:47 AM ET (US)     Profile for Newtauk1  Send Email to Newtauk1     
West Marine is pricey for Anchor Brand wire. Shop it around if you plan on doing a complete re-wire.
jimh posted 04-05-2009 10:54 AM ET (US)     Profile for jimh  Send Email to jimh     
WEST Marine is a retailer, and its stores are staffed by their employees. I do not find that being an employee of WEST Marine is necessarily a guarantee of holding knowledge about electrical wiring practices and electrical wiring design, although I don't think you got bad advice there in this particular case.

I agree with the suggestion to consider other vendors for buying wire, and I would add you might also check other vendors for marine electrical accessories. There has been prior discussion on the topic of where to buy marine grade wire:

Marine-Grade Wire: A Price Survey; Recommended Sources

Over the LINE posted 04-05-2009 09:00 PM ET (US)     Profile for Over the LINE  Send Email to Over the LINE     
Sounds like you are headed in the right direction.

I wired my last boat with Pacer brand wire from Best Boat Wire. I was very happy with delivery time, price and product. Give them a look.

Keep us posted and take some pictures during the job.

Austin Whaler posted 04-06-2009 12:14 AM ET (US)     Profile for Austin Whaler  Send Email to Austin Whaler     
Jimh were you happy with your purchase from They seam to have very good prices, I would just want to make sure I do not get ripped off.

When I go to west marine I usually just go there to look at parts so i can see them, feel them, and pretty much make sure its the right thing and its quality then i order off the internet.

jimh posted 04-06-2009 09:33 AM ET (US)     Profile for jimh  Send Email to jimh     
Many comments about suppliers and satisfaction are given in the separate discussion on that topic. See the article, for which a hyperlink is given above.

Re genuinedealz, yes, I was satisfied with my purchase.

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