Moving batteries under console - 23SF Where to run wires?

[keith]

Hey All. I am moving the batteries under the console and I need some advice from the experts. The current two batteries are in the bilge next to the engine (pictures to come) and they are pretty crammed in there. My question is regarding the new wire runs. I can see there are chases that run under the console to the stern and the previous owner left strings on both sides for more wire. I am concerned that they will flop around in there and possibly wear through the insulation and cause a short, and worst case a fire. I was thinking of opening up the center, fuel tank, panel and running a conduit or two in there and running the wire there. Is this a good or bad idea? The seats are bolted down there and I would have to remove them. Is there going to be room in there?

Thanks! Trying to get her ready for some safe Ocean fishing adventures this year.

[Old'sCool]

On my 23' cc I moved the batteries from stern to under console and ran cables through the wiring chase. I terminated them to blocks mounted front of transom. I calculater the size using Genuinedealz calculator then went up 2 sizes. I did run a secondary chase above the fuel tank and below deck for hydraulic steering hoses. Battery cable run would have been shorter in the secondary chase.

[flyingfrizzle]

I have used hose covers over battery cables or wiring. They have many different types here sold by the foot:

http://www.mcmaster.com/#standard-ca...eeving/=vowikb

[keith]

Thanks for the advice guys.
One more question. I am doing my calculations for amp draws and adding them up. I have a total of around 280 max amps. Is it necessary to run ground wire back to the engine to support that max amp at 3% loss? It would be highly unlikely that I run the downriggers, crab pot puller, trim tabs, both bilge pumps, both vhf's transmitting, radar radarring, all while spotlighting at the same time! Jeez, I get a headache just thinking about all that going on!

[Terry England]

Originally Posted by keith

Thanks for the advice guys.
.......It would be highly unlikely that I run the downriggers, crab pot puller, trim tabs, both bilge pumps, both vhf's transmitting, radar radarring, all while spotlighting at the same time! Jeez, I get a headache just thinking about all that going on!

Keith,
Multi-tasking is a basic criteria for owning a Seacraft. It's right here in the CSC Manual - Chapter IV, Sub-section 121.34b "All Whistles and Bells Shall blown and/or rung simultaniously and without interuption. Maximum voltage drop shall not exceed .000004 ohms"

[FishStretcher]

Originally Posted by keith

Thanks for the advice guys.
One more question. I am doing my calculations for amp draws and adding them up. I have a total of around 280 max amps. Is it necessary to run ground wire back to the engine to support that max amp at 3% loss? It would be highly unlikely that I run the downriggers, crab pot puller, trim tabs, both bilge pumps, both vhf's transmitting, radar radarring, all while spotlighting at the same time! Jeez, I get a headache just thinking about all that going on!

You need power and ground back to the outboard to start it so the cable required for cranking is what is required. I have what you have done and I am almost legal. The 2 or 4 gauge pair to start the outboard is fine. I have fuses after my battery selector switch into a distribution point. The word escapes me but a threaded terminal with cap rated for 500A for hot and ground, one each. From there, appropriately rated *fused* cable to each blue sea systems fuse panel that includes ground. Those are good for 100A each. But I feed both thru a single cable with a 70A breaker. Technically I think I need fuses at the batteries or within 7" to be fully compliant. I also have an inline fused solar panel that will charge batteries with that breaker off, and an inline fused kicker charging harness.

Basically the existing 2 wire outboard starter cable that came with my yamaha is all I use running aft. The current draw is low enough on that to run it thru my battery switch, so I do that.

[keith]

Thanks fish.

I spoke with mercruiser and they said the max amp draw of the starter is 85. I am running #2 for that circuit. I have to run that ground and the ground for all the other 180 amps back to the engine. Just seems excessive but there's not much to do this time of year anyways and it's only money. What else would I spend it on.

[flyingfrizzle]

Originally Posted by keith

Thanks for the advice guys.
One more question. I am doing my calculations for amp draws and adding them up. I have a total of around 280 max amps. Is it necessary to run ground wire back to the engine to support that max amp at 3% loss? It would be highly unlikely that I run the downriggers, crab pot puller, trim tabs, both bilge pumps, both vhf's transmitting, radar radarring, all while spotlighting at the same time! Jeez, I get a headache just thinking about all that going on!

You don't have to figure it that way, You will never run all that at one time. Residential and commercial services are not even rated to carry all the load that it feeds at one time.

I usually use 4 awg on smaller boats with minimal electronics with a single outboard and step it up from there depending on what I am trying to run. 1/0 or 2/0 will carry about what ever you may try to run on a smaller powerboat with lots of electronics and devices. I would use 2/0 for you main feed if there is over 25 feet of cable between your batteries and your distribution point. Most of the time the point where you split the circuits apart is close to the batteries so there is not much voltage drop there. But the supply under the console to your motors you may get some drop. I like to oversize the wire some so if I add anything in the future I'm covered. 4/0 is only necessary in extreme cases but that would give you like a 400 amp capacity. For the starting circuit #4 awg will carry most loads and will be fine for just that one circuit to the motors but you may want to use #2 depending on how far the run is. I would start with 1/0 or 2/0 for the main wiring off the batteries and disconnect switch to the main distribution point then you can step it down from there and come off with smaller wire to each device. Make sure you fuse each item separate and correctly size the fuses too.

Here is something that might help, Chart for wire amp capacity and a wire size calculator:
http://www.genuinedealz.com/voltage-drop-calculator


Here is a neat calculator software that may work, (I have not tried it out yet myself):

http://api.viglink.com/api/click?format=go&jsonp=vglnk_14226536444427&key=cc2 d0a2fcbd156974a46448313b0e067&libId=74d8e582-f9f1-43e6-bf1d-55f6bc0794c5&loc=http%3A%2F%2Fwww.thehulltruth.com %2Fboating-forum%2F37966-battery-cable-size.html&v=1&out=http%3A%2F%2Fwww.midcoast.com%2F ~aft%2Fprogram%2Fwiresz20.zip&ref=http%3A%2F%2Fwww .thehulltruth.com%2Fboating-forum%2F37966-battery-cable-size-2.html&title=Battery%20Cable%20Size%20-%20The%20Hull%20Truth%20-%20Boating%20and%20Fishing%20Forum&txt=http%3A%2F% 2Fapi.viglink.com%2Fapi%2Fclick%3Fformat%3Dgo%26am p%3Bjsonp%3Dvglnk_14226536444416%26amp%3Bkey%3Dcc2 d0a2fcbd156974a46448313b0e067%26amp%3BlibId%3D...

[keith]

Thanks guys. I worked on it yesterday and moved the batteries. There is a ton more room to work on the engine and the batteries can actually be maintained now! One battery didn't have any visible water in it!! Couldn't get to it for maintenance before. Going to replace both 2006 batteries. Still thinking about where to mount the Perko...
I also did some work to the dash. I relocated the Lenco switch, added bilge pump switches (plus two 2000 gph pumps), and added a high water alarm.
I was planning on keeping some of the wires running through to the stern but I am thinking of just scrapping all of them now that I am this deep.
I have a question (or another question...). I pulled off the floor board in between the engine cover and the console to see if I could run a conduit in there (not going for this right now, too tight.) The previous owner, a friend of mine, put silicone down under it and in the seam on the top. He really likes silicone (picture below). What do you recommend for sealing this floor board from water intrusion to the tank area?