Re-wiring/battery relocation

[Will Fish]

I'm thinking about re-wiring my boat. It's a 21' cuddy cabin I/O, with a fresh motor and outdrive. I want to relocate 1 of my batteries towards the bow, since it gets in the way next to the motor, and I'd liek to be able to remove the rear seats for added fishing room. I have a dual battery switch already in place, with all load added to the common post on the switch. The larger battery does not fit in behind my back panels, and I would ideallylike to move towards the bow would be for accessories and house loads, and the smaller battery that remains in the stern would be for crank. I have 2 fused bus bars under the dash for the accessories. Under the dash is a wiring nightmare between all of the gauges switches and ignition, and i want to clean it all up and make some sketches for future reference.

1. Is this something that could be feasible?
2. How would I wire the engine harness? I think the ignition is wired directly to the starter?
3. Since I need to move the larger battery, should I keep that as my crank, eventhough it will be mover 12'-15' away from the motor, and relocate the fuse panels to the stern?

Any information would be helpful, as I have not really gotten into the wiring yet, but it is a mess and do need to at least clean it up.

 

[glenn property of pam]

Re: Re-wiring/battery relocation

generic ans is that you can mount the battery where ever you like then just upgrade the wire between that battery and the dual battery switch. The battery will take more abuse up front but thats not a real big deal. if you mount in the front area make sure its well secured then double the distance and upgrade the cable for that lenth of voltage drop.

custom ans will require a better understanding of what battery load you have and what you plan to use it for. what works for one person will not always work out best for you and your boat. With out knowing why you have 2 batteries and what you plan to do with them theres way to many options so tell us what you have planned and we will help you out (trolling/livewells/stereo/back up starting/etc)

 

[Silvertip]

Re: Re-wiring/battery relocation

You are advised to "fully" understand the existing wiring before you launch off on a rewire project. I don't think you understand that there are TWO electrical systems on a boat (three if you have shore power). The engine has it's own electrical system. It gets its power via the large battery cables from the cranking battery. The harness between the engine and helm powers the ignition and the instruments. That system is not intended to power anything else. The second system is the one that feeds the fuse panel at the helm. It gets its power from the smaller #8 or #10 wires that run from the cranking battery, COM terminal on the switch, or from a house battery depending on how things are configured. There are many diagrams in this forum that discuss and illustrate these systems so use the search feature and check the stickies at the top of the forum. As for moving the battery, you merely need longer cables.

 

[Will Fish]

Re: Re-wiring/battery relocation

I currently have a 2 battery set up. Ideally 1 is for the motor and crank, and the 2nd for accessories, however there are accessories on both batteries, and the motor will crank on either battery or both. Should I dedicate say batt#1 for crank only? Would this elimiante my options of cranking on both batteries or batt#2?

Aside from the motor harness, I have the following installed:
1. fishfinder/gps
2. VHF radio
3. am/fm cd player - 4 speakers
4. running lights/anchor light/courtesy lighting
5. bilge pump - connected to a float for automatic, and a manual override
6. salt water wash down pump
7. 12v ciggarette lighter/aux
8. Outdrive Trim
9. Tach, Volt Meter, Gas, Gauge, Temp, Oil Pressure gauge, Water & Oil Alarm - All lighted
10. Blower

 

[Silvertip]

Re: Re-wiring/battery relocation

I assume you have a dual battery switch so ALL accessories should be attached to the COM terminal on the switch except perhaps an automatic bilge pump which would go to the largest capacity battery directly. The switch can therefore select either or both batteries to start the engine, charge either or both, or run accessories from either or both. If you have an ACR then you split up the loads to each battery however you wish.

 

[glenn property of pam]

Re: Re-wiring/battery relocation

im with silvertips on keeping all acc on the com terminal of the dual battery switch.

 

[Howard Sterndrive]

Re: Re-wiring/battery relocation

If it were me, instead of moving ONE battery up front - I'd just remove the 2nd battery and probably the switch too. Hook up one battery the way the boat was originally equipped, and just carry a nice booster pack on board. Put that booster in the bow or wherever you want.
Long battery cables are expensive, heavy, and a fire hazard if not run properly.

A good booster pack can start a tow vehicle, stranded boater, inflate a trailer tire. Mine even has back up navigation lights and a nice LED work light as well as two 120V AC outlets, USB charger etc. Cheaper than the long cables. Copper is dear these days.

 

[Will Fish]

Re: Re-wiring/battery relocation

I do keep a charger on the boat for emergencies, but do not want to eliminate a battery.