Moving batteries. Re-rigging / Wiring question? - The Hull Truth

Mr. Demeanor · 10-24-2009, 12:29 PM

Reference my other thread on moving my batteries from the bilge to the console, I dug into the wiring a bit today to get some measurements so I can determine what size battery cable I need. I looks like I will be going up from the current 2awg to 1awg.

There are some things I found that somewhat confuse me and I think I can do this a little different.
The way it is rigged right now, there are two positive cables, one running from each battery to the battery switch. The negative terminals are tied together with a 2awg jumper and then each negative terminal has its own 2awg cable that runs to a negative buss next to the battery switch.

Batteries in bilge. The second is behind the first so I cant get a pic:

Battery switch and negative buss mounted under back seat:

The negative cables from the batteries are at the right end of the buss. I do not understand the need for two negative 2awg cables that are tied together at both ends.
There are two cable at the far left end of the buss as well. The one with the red tape runs to the console where there is another negative buss. The second goes to the engine.

Negative buss under console with red taped cable coming from buss under back seat:

With both batteries mounted under the console near the negative buss, shouldn't I be able to run one 1awg negative cable from the batteries (which are tied together) to the nearby buss and from there to the negative buss under the back seat? Or should I run one 1awg from the batteries straight back to the negative buss under the back seat and leave the cable running back to the buss under the console?

Secondly, do I need two negative cables running from the batteries as it is currently rigged?

I like the possibility of eliminating that red taped negative wire as I could use it to pull my new cable when I replace everything.

Mr. Demeanor · 10-24-2009, 07:59 PM

I have looked at a bunch of wiring diagrams for dual battery setups and they all show a common ground cable. I am not sure why Fountain ran two (one from each battery)?

I also dont like how the engine ground is drawing through the buss. It has worked fine for 6 years but I will at least be making a direct connection (put them on the same post) between the ground cable from the batteries and the engine ground.

LI32 · 10-25-2009, 05:45 AM

One ground cable running from battery A to battery B and then a second from battery B (or A) to the buss is all that is needed. Personally, I would run one cable from each battery to a power post (Blue Seas #2002) and from there one cable to each buss plus one cable directly to the engine.

Elusive · 10-25-2009, 07:28 AM

Looks like alot is going on with the switch. Might want to address that now as well

If the current system does not allow automatic charging of the house batt, replace the switch with a cluster

http://www.bepmarine.com/Clusters-180.html

Neg from both batts tied together

Neg from engine to neg on starting batt

Neg to bus bar to neg on house batt

For the wires that remain on the buses, I would loosen the individual ground connections, apply dialectric grease, re-tighten and the spray regularly with CRC or similar. They are probably OK (I like the heat-shrink crimps) but why not be sure

Mr. Demeanor · 10-25-2009, 07:57 AM

I already have a BEP VSR. Its just to the right out of the pic. That contributes to the wiring coming from the battery switch as well as my bilge pumps being hard wired. Fountain does not excell in the area of neat, logical wiring. Anyoen who thinks a nice looking woring job is purley for looks never had to get into a mess like this.

knotreel · 10-25-2009, 10:16 AM

I like the idea of tyeing the battery grounds together plus running two grounds to the buss. I have mine rigged that way and i think it offers two good things. One, it provides redundancy on a critical system and secondly it offers less resistance for starting loads. Do you need this, no, but I like the peace of mind. For the power side I have a butt connector on engine positive where I have added the extra 10 or 12 feet I needed to to run the engine power wires to my console mounted battery switches.

Mr. Demeanor · 10-25-2009, 11:08 AM

Quote:

Originally Posted by knotreel

I like the idea of tyeing the battery grounds together plus running two grounds to the buss. I have mine rigged that way and i think it offers two good things. One, it provides redundancy on a critical system and secondly it offers less resistance for starting loads. Do you need this, no, but I like the peace of mind. For the power side I have a butt connector on engine positive where I have added the extra 10 or 12 feet I needed to to run the engine power wires to my console mounted battery switches.

Ancor website has a cable calculator. I put in the 170amp starting load listed in my Opti's shop manual and the approximate length of the battery cable run. I am right at the limit of a 2awg so I will bump up to 1awg. I dont care for the idea of a butt connector on the most critical cable on the boat. If I did that, it would also be inaccessable under the deck.

I think I will run two 2awg ground cables (one off each battery) to the existing buss under the console since I already have the cables. Run one 1awg from that buss to the buss at the transom where my engine ground attaches. That should provide good ground. It sucks becasue I alreay have that long 2awg ground (the one with red taped ends) running from the buss under the console to the buss under the back seat. If I was confident it would supply enough it would really cut down on the cost of this little project.

knotreel · 10-25-2009, 02:52 PM

Well you could just get another #2 cable to match and add to your other ground. That should be good current wise as long as you don't start motors at the same time? I still think two are better than one. As far as butt connectors on the positive engine cables, they don't make them long enough so the factory cables will not go to any center console but except maybe a bay boat? So my guess is you may already have butt connectors? It is my personal belief that the HD tinned butt connectors covered with some industrial adhesive shrink tube make a nice joint. But that's just my opinion. Anyway good luck on your project and who knows your boat might run even if you don't follow my advise?
opps, just re-read your post, scratch the part about getting the other cable to match. If I were doing this job I would run two new grounds directly from the batteries new location to the rear buss without a connection under your seat, that way just one connection to ground the engines. Two wires?, one wire?, that is what I would do.

Mr. Demeanor · 10-25-2009, 05:22 PM

Not sure what you mean about the cables not being made long enough? You can buy the cable by the foot in any length you need. It comes on large spools from 25' to 100'. Just cut to length and add your lugs. A 25' spool f 1awg Ancor cable is about $160 though!

knotreel · 10-26-2009, 07:22 AM

I meant the factory positive cable on outboards are not long enough to reach batteries mounted in the console. Maybe a bay boat but not an offshore size boat.
And to make them long enough I think almost every offshore size boat has the butt connector you said you didn't want. My point was (I think) that butt connectors to extend your positives are OK in my world at least. Yeah, it would be better to not have to make a splice but what you gonna do if you want your batteries up in the console where they should be. Sorry, my writing style sometimes even confuses me.
Good luck and have fun with your project.

Mr. Demeanor · 10-26-2009, 07:46 AM

Quote:

Originally Posted by knotreel

I meant the factory positive cable on outboards are not long enough to reach batteries mounted in the console. Maybe a bay boat but not an offshore size boat.
And to make them long enough I think almost every offshore size boat has the butt connector you said you didn't want. My point was (I think) that butt connectors to extend your positives are OK in my world at least. Yeah, it would be better to not have to make a splice but what you gonna do if you want your batteries up in the console where they should be. Sorry, my writing style sometimes even confuses me.
Good luck and have fun with your project.

Gotcha

If I was sticking with 2awg it would be a possibility but 2awg is rigt at the limit and 2awg with more connectors would likely reduce the amp carrying capacity even more. I would greatly reduce the cost. I need to start looking for a deal on some 1awg cable.

marvin177 · 10-26-2009, 08:13 AM

Quote:

Originally Posted by Mr. Demeanor

Gotcha

If I was sticking with 2awg it would be a possibility but 2awg is rigt at the limit and 2awg with more connectors would likely reduce the amp carrying capacity even more. I would greatly reduce the cost. I need to start looking for a deal on some 1awg cable.

The best prices I've found on wiring supplies is genuinedealz.com they are in Brunswick GA and have free shipping. I'm not in anyway affiliated with them just a satisfied customer. They will also install terminals on custom lengths.

Mr. Demeanor · 10-26-2009, 10:55 AM

Thanks, I will check them out. There was a boating flea market here on Saturday but work got in the way. I was hoping to score some battery cable.

Joe · 10-26-2009, 01:00 PM

Looks like a lot of corrosion on that Pos battery terminal..might want to take a look at that.

Mr. Demeanor · 10-26-2009, 01:33 PM

There is no corrosion on the terminals. You cant even see them???? The are covered with rubber boots. The sun is hitting the pos and kind of washed out the pic if thats what you mean???

bluewaterpirate · 10-26-2009, 03:39 PM

I replaced the primary wire run aft from the batteries to my 225 Opti using Anchor 2 awg wire, the run was approx 18 feet. My batteries we already located in my console so cleaning everything up was quite easy. I used a BEP 716A switch ... been working great for 4 years plus. I've replaced my Cabelas AGM's this season replacing them with Odyssey AGM's.

Mr. Demeanor · 10-26-2009, 09:44 PM

Looks nice and I am happy it works but your are definitely undersized on wire. Using the Ancor calculator, 13' is the limit for a 170amp load which is what the Opti is rated at for starting. Combine that with having some electronics running while starting and I am surprised you havnt had any issues. I have Raymarine electronics and they are very voltage sensitive so I am not taking any chances.
http://www.marinco.com/files/applets...alculator.html
I have the same Guest charger. Wouldnt own a boat without one.

bluewaterpirate · 10-27-2009, 07:48 AM

was installed by Whaler in the original install. Went stock with what was there. Spend the extra money .........

Wake up ... why in the hell would you want you electronics on during startup??????????????? My electronics is isolated from the start battery to begin with unless I choose to parallel it into the start circuit using the BEP Emergency Parallel Switch setting.

Mr. Demeanor · 10-27-2009, 09:03 AM

Mine are isolated with a BEP vsr but if #1 died and I had to run on #2 alone everything would be drawing from #2 and that long run on a 2awg could get me close to a problem. One of the reasons I have them isolated is that I drift fish a lot and restarting electronics constantly got old real fast. This is a known issue with the Raymarine A65. Any power fluctuation shuts it down. The cost difference if I buy from genuindeals.com is $1 per foot.

Mr. Demeanor · 10-31-2009, 03:20 PM

Made a little progress today. The brackets were done so I cut and routed the King Starboard. What a mess that stuff creates but its easy to work with. There is 3/8 between the new supports and the tank. That gives me my room for bolt heads. A couple strips of weather stripping will fill the gap so the tank is held down firmly.
I had to notch the one support leg for the water fill fitting. After I took these pics, I drilled all the fastener holes. Chamfered all the holes in the aluminum and Starboard material. So far so good.

I had the tank completely out and was able to stand on this platform with it sitting over the tank on the concrete. I weigh about double what the batteries do so I think its more than enough.
I will finish getting this mounted up and need to order battery cable. It will probably be awhile before I actually move the batteries. Just doing a little at a time instead of my usual marathon project timeline!
Just got a new camera so I have been playing and taking pics of everything.