Jump to content

Battery setup


Freshtrax

Recommended Posts

So I'm rigging my new boat. I have a 15 hp kicker with charging and electric start. 302 ford main motor, fish finder, stereo, vhf, bilge pumps, blower and and lights to run. I'm not sure what to do with battery's. The way the boat is setup now the fuse panel is hooked up to main engine battery. Should I just run the whole boat of 2 battery's in parallel. Or should I have a separate battery for the main ( starting only). And a separate battery for the kicker and boat electronics? The kicker will be the motor running 98% of the time.

Link to comment
Share on other sites

In parallel using one of these, between the two batteries.

 

Battery switch.jpg

 

That way you can isolate the main engine battery, while using the kicker. If the kicker cannot keep its battery and the electronics' battery charged, with its low rate of charge system; the main engine battery will not be drained. When using the main engine, start it with its battery and then switch the selector to both batteries so the larger charging system can bring both batteries back up to full charge.

When storing the boat, switch the selector to off; now all electrical is dead and no forgotten radio or fishfinder to kill your batteries.

 

Dan.

 

 

Link to comment
Share on other sites

The best way to setup a 2 battery system is use the switch as others noted, but also add an ACR. Blue Seas has an Add-A-Battery kit that comes with a switch and ACR for around $110. The switch works as others have noted but the only problem with switch only is that only one battery really every gets charged. So what you should do is this....run the alternator, kicker charging and wire to the fuse panel off the COMMON post on a switch. Hook the two batteries to post 1 and 2 respectively and then run the ACR between the batteries. With this setup, run your switch on 1 (or 2) all the time, the alternator and kicker will constantly charge that battery, and the house will run off that battery, and the ACR will dump any excess current to the other battery to keep it topped up. If you have a battery emergency, switch to BOTH on the switch and you will get juice from both batteries to get started. The alternative to this is to run the main engine off one battery, the electronics and kicker etc off the other battery but still put in the ACR and switch for better charging and being able to start in emergencies. This is a bit less risky that you will drain a single battery down but is a bit more inconvenient to operate.

 

It will be pretty minimal wiring change from what you have going either option.

Link to comment
Share on other sites

I agree. Good thread.

 

Not to hijack the thread, but I was thinking of moving my engine (crank) battery, up to the bow of the boat where my second battery is.(keep the bow down/ plane faster) Question here is this, would the length of wiring required, affect any charging aspect of the battery?

Link to comment
Share on other sites

The length of run effects what wire gage can safely be used for the wire run. You want to look up what size will give you less than 3% voltage loss at the length of run for the current the cable will carry. I would guess need 2 gag wire for black and red. Depending how far it is it could be pretty expensive.

Edited by Consigliere
Link to comment
Share on other sites

I agree. Good thread.

 

Not to hijack the thread, but I was thinking of moving my engine (crank) battery, up to the bow of the boat where my second battery is.(keep the bow down/ plane faster) Question here is this, would the length of wiring required, affect any charging aspect of the battery?

 

I don't think that charging would be an issue. There may be an issue with starting the motor. Starting the motor requires a lot of current; extra length adds extra resistance. You may need a heavier gauge wire.

 

The battery may not last as long if it is the bow of the boat. The extra pounding it gets in the front may shorten the life of the battery.

Link to comment
Share on other sites

My boat is designed to have 2 batteries on the bow for the 24V trolling motor. Non issue I believe. The original owner wired one of the 12 volts at the bow to be used as an emergency starter for the 115 on the back, those wires are very heavy gauge, at least 5/8 inch in diameter.

Link to comment
Share on other sites

Princess Auto has welding cable at a decent price. #4 cable ($2.49 a foot); that would be more than enough to handle the current load for the main motor's starting circuit.

I put the battery for my 50 Chevy in the trunk; I ran a #4 cable from the trunk up to the underhood electrical centre; for all the electrical, to start & run this fuel injected, computerized V8 that I installed.

 

Dan.

Edited by DanD
Link to comment
Share on other sites

Princess Auto has welding cable at a decent price. #4 cable ($2.49 a foot); that would be more than enough to handle the current load for the main motor's starting circuit.

I put the battery for my 50 Chevy in the trunk; I ran a #4 cable from the trunk up to the underhood electrical centre; for all the electrical, to start & run this fuel injected, computerized V8 that I installed.

 

Dan.

In fresh water and smaller bodies of water it is likely you can get away with cheap material but it is not good practice to use automotive materials on boats. Marine wire has finer strands for more durability against vibration and maintains its strength for longer. It is also tinned to prevent corrosion. Again you can probably get away with it but you also have a higher chance of a fire by using lesser materials on a boat. Personally for the big cables I will always get the right materials. There is too much current in those to mess around. With the 16-22 wire I you can cheap out and not worry too much
Link to comment
Share on other sites

In fresh water and smaller bodies of water it is likely you can get away with cheap material but it is not good practice to use automotive materials on boats.

 

It's not automotive; it's welder's cable.

Very fine braid (don't know the #) and thick walled insulation. Solder a copper or brass lug on the end and then shrink tube the shank of the lug and 2 or 3 inches down the cable insulation. Been using it for years in all kinds of weather; welding trailers out in the yard. Last cable is something like 12 or 15 years old and not a sign of corrosion or insulation cracking.

If there's still a concern with aberration, rubbing through the insulation; run the cable through a length of 3/4" automotive heater hose and secure it properly.

I do agree with you about salt water applications; extra precautions need to be taken.

 

Dan.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recent Topics

    Popular Topics

    Upcoming Events

    No upcoming events found

×
×
  • Create New...