electrical grounding question

[Anonymous]

Quick question regarding electrical grounding on a wooden boat...
So I am back into the wooden boat build hardcore for awhile. The boat is completely wooden. I will have a battery for Minn Kota, and a seperate smaller battery not typical of your usual size marine battery, this battery will be for a cd player/tuner. Usually when you install electronics like a cd player the deck has a ground wire... I can't see what I would ground it to in a wooden boat?? OK... so if I run an in-line fuse between the battery and the deck, am I OK? So if there is a problem it would just blow the fuse right?
Yes... I know it is overkill to put a cd player in a little wooden boat, but I've already cut speaker holes and I'm on my way!:geek:

Oh, BTW... I am trying to figure out the power draw from the cd player. I want to know what the draw is so that I can make a proper choice on the battery to purchase. i.e. (certain amout of amps per hour, etc.) I have looked at the specs. on the Sony deck. All I am getting is 52 watts X 4, (Use a 12 V Marine battery, etc.) I am not talking about a big old marine battery like the size of what you normally see on cars or boats... You can purchase much smaller batteries like motorcycle size... and purchase them in whatever amps per hour range you need...... Just can't figure where in the manual it would say what the draw from the deck is? If anyone has a guess on what would be a sufficient size (amps per hour 12 volt...) please chime in.

[Anonymous]

If there is no metal in the boat like a metal deck, then a ground wire HAS to be run alongside the power wire to each and every electrical device. They make wire for this purpose, a 'dual-wire' that is insulated and molded together in the same insulation. It can be gotten at trailer supply stores, auto parts stores-usually, and should be able to get it at marine stores too. Or maybe Radio Shack. I've used the same type stuff to wire lights on trailers.

[The Quadfather]

If there is no metal in the boat like a metal deck, then a ground wire HAS to be run alongside the power wire to each and every electrical device. They make wire for this purpose, a 'dual-wire' that is insulated and molded together in the same insulation. It can be gotten at trailer supply stores, auto parts stores-usually, and should be able to get it at marine stores too. Or maybe Radio Shack. I've used the same type stuff to wire lights on trailers.

Tom, OK....? so "A ground wire has to be run alongside the power wire to each electrical device"
The power wire will be like all of 10" from the deck to the battery. If this 10" ground wire is running from the deck..., where is the other end attached to?

[Anonymous]

The negative post of the battery.

Or what I would do is make a 'ground strip' with a #10 wire, or bigger from the battery to the ground strip. The ground strip should have 5 or 10 teminals on it for grounding other devices.

Then make a power strip for the same idea with an in-line fuse between the power strip and the positive post of the battery. As well as in-line fuse on each device used.

Then you can attach other things like maybe a light.

[The Quadfather]

Thanks.. OK, let me dwell on this awhile.

[The Quadfather]

Thanks for the info. on grounding....
but back to the second question. I want to figure out what the power draw in amperage that I need to keep in mind for a battery purchase. Realize that I am not talking about a big old marine 12v battery. I am talking about buying a much smaller 12v batt. that is rated in amps per hour.
So that being said,, is it true-- Watts/Volts = Amps? The deck is rated at 17 watts RMS X4. So does that mean does that mean 68 watts divided by 12v = about a 5.5 amps per hour battery?#-o
I admit now that I transfered out of electronics in the 10th grade.

[Amx]

Yup. My formula is in the other computer so I can't post it here. But an internet search for 'electrical formulas' should work, or 'watts volts amps' might do it too. I can never remember the proper formula anymore, been too long since I did it.

[SmanOhood]

http://www.uglys.net/Conversion.aspx

[Amx]

bottom of page;

http://www.elec-toolbox.com/calculators/calculators.htm

left column;

http://www.angelfire.com/pa/baconbacon/page2.html

then right column;

http://www.eatonelectrical.com/NASApp/c ... ife/BLForm

search results;

clickie here

nutter search - basic lectrical formulas and stuffies things

[The Quadfather]

http://www.lowcostbatteries.com/product ... 012-5f.htm

I'll just start here... if I go wrong, at that price i can just jump up in amps/hour.
Thanks folks.

[SmanOhood]

Not sure why you wouldn't just get a bigger battery anyways.Yes I know its wood but give up the senko rods and! you will have plenty of room.Do you have a cell phone capable of pandora?A dewalt cordless radio with 1 18volt XRP battery will last all day.

[The Quadfather]

Not sure why you wouldn't just get a bigger battery anyways.Yes I know its wood but give up the senko rods and! you will have plenty of room.Do you have a cell phone capable of pandora?A dewalt cordless radio with 1 18volt XRP battery will last all day.

The reason for not just having a bigger battery to cover the motor, and the radio, is that one battery covering both items will lead to noise in the speakers from the Minn Kota. Didn't understand the Senko rods thing... but yes, I do love to fish me some Senkos.

[Marc Martyn]

Fire off a PM to Eric (Gisteppo).

http://www.washingtonlakes.com/forum/ya ... e1188.aspx


He has gone through this many times and probably would have some very good suggestions. He has built many wooden boats.

[hewesfisher]

Chris - I replied to your PM, but will do so here as well. What you are creating is essentially a "boom box" with a separate battery pack. All you need to do is run the power leads from your deck direct to the battery terminals. You do not need a ground strip or additional terminals unless you intend to run other components off this battery which is something you said you were not going to do. Even then, you would not need additional terminals, all you would need to do is run power leads direct to the battery as long as any other components didn't involve an electric motor or an RF generating device (like a marine radio or sonar transducer) that might cause interference.

Practice the KISS method here, you're goal, unless I misunderstood your PMs, is to use the battery solely to power the deck. In that case, one wire each from the battery to your deck's power leads with an in-line fuse holder in the lead running to battery +. Fuse at the deck mfr's recommended amperage.

It's really that simple.

[hewesfisher]

So that being said,, is it true-- Watts/Volts = Amps? The deck is rated at 17 watts RMS X4. So does that mean does that mean 68 watts divided by 12v = about a 5.5 amps per hour battery?#-o
I admit now that I transfered out of electronics in the 10th grade.

I missed this question in my earlier reply. Yes, your deck would pull about 5.5amp hours, 5.67 more precisely, so a 12 hour listening session at full volume would "consume" roughly 66 amps at 12v. A more realistic listening level might consume, say 1.5amps, and for a 12 hour day that's just 18 amps and now you're talking about riding lawnmower or motorcycle size batteries. Hit your local WalMart for something along those lines with around 25 - 35 amp hour capacity and you'll have plenty of "tune time" on the water.