Rewiring boat

Discussion in 'Boat Modification Journal' started by Seth, Mar 4, 2008.

  1. Seth

    Seth Active Member

    Messages:
    1,807
    State:
    Owensville, MO
    I'm going to rewire my boat and wanted to double check a couple things first. I have a 24/36 volt trolling motor so I run two deep cycle and one starter battery in my boat.

    I want to have two of the batteries hooked up to the positive bus bar so I can hook up different accessories to each one. Will this work as long as I keep the grounded wires separated?

    Sometimes i take out the deep cyles to reduce weight and I'd like to still be able to use my bilge pump and runnings lights by hooking them up to the starter battery.

    I have a diagram drawn up of how I want to do this. Let me know if it will causes interference problems with my fish finder or anything else. If it's unclear just ask me what you need to know and I'll explain it better...hopefully.

    thanks
    Seth
     

    Attached Files:

  2. wolfman

    wolfman Well-Known Member

    Messages:
    9,081
    State:
    Triadelphia, WV
    Name:
    Walter Flack
    I would keep the starting battery seperate from all other accessories. Also I would run the fish finder wires directly to one deep cycle battery with a 3 amp in-line fuse. This will reduce interference you might have through the bus bar.
     

  3. Seth

    Seth Active Member

    Messages:
    1,807
    State:
    Owensville, MO
    Ok I can extend the fish finder wires a little to reach a deep cycle battery no problem.

    So is the only way for me to run the bilge and running lights on the starting battery to just get another positive and negative bus bar and hook them straight to the starting battery? Hooking up two battery positives to the bus bar won't work?
     
  4. JAYNC

    JAYNC New Member

    Messages:
    1,312
    State:
    Newport N.C.
    I run all my accessories on my starting battery, nav lights, stereo, depth finder, bilge, aerator. You name it, its on there. Buy a marine master starting battery, mine has been going very strong for almost three years now without a single problem, it also helps to have a good on board charger such as a dual pro. Just a suggestion. You could have just one positive and one negative going from your starting battery to your bus bar and hook everything up accordingly. Just use good quality hardware such an ancor, and put di-electric grease on all your connections before you crimp or tighten any screw. Make sure all wires can not get chaffed anywhere and you should have good boating for years to come. I only use the trolling motor batteries for the trolling motor. But thats just me.
     
  5. wolfman

    wolfman Well-Known Member

    Messages:
    9,081
    State:
    Triadelphia, WV
    Name:
    Walter Flack
    Not really, you can run your lights, bilge and livewell pumps and 12volt outlet from the fuse panel to the bus bar off deep cycle battery (A).

    Run the fish finder directly off deep cycle battery (A).

    Run your trolling motor off of deep cycle battery (B).

    If it was me, I would only use the starting battery for cranking the motor only.
     
  6. Seth

    Seth Active Member

    Messages:
    1,807
    State:
    Owensville, MO
    Well I use all three batteries to run my trolling motor most of the time unless I for some reason only have the starting battery and one deep cycle battery. I'd have to put in a 4th battery to my boat to have a battery free from the trolling motor, which I would rather not do since they weigh so much. :embarassed:
     
  7. brewfish

    brewfish New Member

    Messages:
    61
    State:
    fl

    What's your reasoning for only using the deep cycle for the trolling motor and everything else on the starting battery?
     
  8. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    I don't run a trolling motor, but I run everything off of my starting battery. I don't have a ton of accessories other than nav lighting, spot light, and depthfinder, though. I usually night fish so I have my anchor light on if I'm in the channel, but I haven't had any issues running on one battery. It's a deep cycle and I throw it on the charger every couple of weeks to keep it topped off. My depthfinder shows me battery voltage so I can keep an eye on the charging system of my boat while running as well as battery voltage while I'm sitting.
     
  9. CountryHart

    CountryHart New Member

    Messages:
    10,914
    State:
    missouri
    I rewired my ole tub last year. Started with a fuse block i got at NAPA and run them one at a time. Everything runs off the cranin batt and trolling motor runs by it's own batt. Never had any probs. YET. The fuse block helped my prior problems.
     
  10. SkipEye

    SkipEye Well-Known Member

    Messages:
    7,525
    State:
    Winfield, MO
    Name:
    Darryl
    Seth, You obviously made an error on your drawings. If not you have some issues going on.

    If you want to run the positive from two different batteries to the same bus they MUST be wired in parallel.

    You seem to be talking about a bank of three batteries wired in series (to provide 36v for your trolling motor).

    It looks like to me that you are planning on running the positive lead from Battery 1 and Battery 3 to the same BUS!!!!:crazy: While they are both at 12v with respect to their own negative terminal, those two positive post will have a difference of potential of 24v.

    I'll bet you see a ton of sparks when you go to hook up that second battery to the bus (plus a melted bus bar)!:0a34:
     
  11. Seth

    Seth Active Member

    Messages:
    1,807
    State:
    Owensville, MO

    OUCH! Glad somebody mentioned that to me. I don't know much about wiring electronics and battery voltages and all that.

    I guess I am just going to not worry about running anything from the starter battery and just keep everything hooked to one of the deep cycles. This is how I have everything right now and it works fine.

    I've read that trolling motors will cause interference with a fish finder. Does it matter if I have the fish finder hooked to one of the deep cycles batteries AS LONG as I don't have the trolling motor running? I always do my graphing while running the outboard and not the trolling motor anyhow.

    Also what does running batteries in parallel mean exactly? Does that mean that I should hook the starting battery negative to the negative bus like I have the deep cycle battery?
     
  12. wolfman

    wolfman Well-Known Member

    Messages:
    9,081
    State:
    Triadelphia, WV
    Name:
    Walter Flack
    Your cables from the fish finder should be routed away from all other power wiring. You can still use the same battery and shouldnt have any interference.

    In the SERIES CONNECTION, batteries of like voltage and Amp-Hour capacity are connected to increase the Voltage of the bank. The positive terminal of the first battery is connected to the negative terminal of the second battery and so on, until the desired voltage is reached. The final Voltage is the sum of all battery voltages added together while the final Amp-Hours remains unchanged. The bank's Voltage increases while its Amp-Hours, Cranking Performance and Reserve Capacity remain unchanged.

    In the PARALLEL CONNECTION, batteries of like voltages and capacities are connected to increase the capacity of the bank. The positive terminals of all batteries are connected together, or to a common conductor, and all negative terminals are connected in the same manner. The final voltage remains unchanged while the capacity of the bank is the sum of the capacities of the individual batteries of this connection. Amp-Hours Cranking Performance and Reserve Capacity increases while Voltage does not.
     
  13. Seth

    Seth Active Member

    Messages:
    1,807
    State:
    Owensville, MO
    Thanks alot Wolfman. I understand that completely. :big_smile:
     
  14. duxsrus

    duxsrus New Member

    Messages:
    1,014
    State:
    SW Ohio
    There's many ways you could wire up your accessories, just don't do it like your drawing shows. As mentioned if your bus bar doesn't melt down, you're still going to have way too many volts going to the accessories and for sure will fry them. If you're unsure of DC electricity, it might be a best to have someone help you that does.
     
  15. wolfman

    wolfman Well-Known Member

    Messages:
    9,081
    State:
    Triadelphia, WV
    Name:
    Walter Flack
    no problem, I will submit a article in the library section. By the way, "nice cat" in your avatar. Good luck with your project
     
  16. SkipEye

    SkipEye Well-Known Member

    Messages:
    7,525
    State:
    Winfield, MO
    Name:
    Darryl
    It will melt something as it will be a 24v direct short, no resistance, therefore high amps at battery capacity!

    Ever short your jumper cables together? Double the voltage potential and short them together and you'll see the results.:eek:oooh: