Remote Battery, Perko and Junction Block

[Grant Brown]

I have a remote deep cycle battery located in the bow of my boat for better weight distribution. I am running 8 ga wires to the perko switch.
I have all of the power feeds (2 fuse blocks), the trim tabs, the fish finder, downriggers all connected to the starter wire. The grounds are all hooked up to the neg battery terminal.
I would like to have these feeds taken off of the starter/battery and coming off a junction block instead.
Can anyone point me to a wiring diagram that shows how to set it up?

Thanks,
Grant Brown
Vancouver, BC

 

[Silvertip]

Re: Remote Battery, Perko and Junction Block

Wow! You are going overboard with what may sound like a great idea but there are lots of "why" questions here. So lets get some clarification:

1) So what is the Perko switch for if you have accessories wired to the batteries? By doing that you defeat the purpose of the switch.

2) If you have only #8 gauge wire going up front and you try to start the engine with the switch set on BAT 2 (or BOTH for that matter) that 8 gauge wire will go up in smoke like a July 4th smoke bomb. This is true however, provided you have the switch installed as it was designed for, not as you intend to use it (which is not clear at this point).

3) Why two fuse blocks? You need two only if out of space in the first one.

Now then -- here is a diagram of how the two batteries, engine, and a battery switch are wired. WARNING: every cable you see in this diagram is the same size as the two going to the engine. #8 will not do here. All of your accessories get connected to a fuse/breaker panel, but the feeds to the +12 volt buss on those panels comes from the COM terminal on the switch, not directly from the batteries. The only thing you don't want wired to the switch is a automatic bilge pump. It goes directly to either battery. The advantage of this wiring scheme is OFF turns off everything (except the bilge pump). BAT 1 setting powers everything and the engine charges ONLY BAT 1. Same thing happens if you select BAT 2. If you select BOTH, the engine charges both batteries and all accessories are powered by both batteries. You would typically start the engine on BAT 1. Switch to BAT 2 to ensure it gets charged while you run to your destination. Consider BAT 2 your house battery. While fishing or doing whatever you are doing, BAT 1 (starting battery) is out of the loop so there is no danger of it not starting the engine.
Rethink your plan as what you are considering doesn't seem practical and in a way, dangerous.

 

[Grant Brown]

Re: Remote Battery, Perko and Junction Block

Let me clarify:

This boat was an electrician's nightmare. When I bought it last December, I found accessories wired with speaker wire, splices covered with masking tape and roofing nails nailed into aluminum panels to hold wires out of the way. Under the dash, taps were taken off anywhere that was hot. There were toggle switches controlling toggle switches. I actually took 4 out that didn't seem to do anything. All of that nastiness has been fixed with tinned wire, soldered joints and sealed heat shrink tubing and is considerably neater and tidier than when I got it.

The wires for the remote battery are close to if not the exact same size as the battery wires. I must have been mistaken when I typed #8. They are from a power supply system used in baggage handling at an airport. There are actually 4 conductors and I'm only using 2 (I was too lazy to strip all the cable out to separate them). I could double them if needed but that might be overkill. The lugs I used are copper, hammered and then soldered. This setup has been in the boat all summer and I've had no trouble when starting from number 2 battery (I did have a weak battery at one point but it's been replaced).

Everything is switched by the Perko except the bilge pump. It is just that the grounds are all on the number 1 battery, and the supplies are all on the starter motor terminal. The starter terminal doesn't have much room left and it just seems wrong to keep running more stuff from it. Currently it has the down riggers, trim tabs, the Mercruiser harness, the tilt/trim and the 2 fuse blocks. All are switched by the Perko off, battery 1, both or battery 2.

One fuse block is under the console at the helm for lights, vhf, gps, dash etc, one fuse block is under the port side console for the fish finder and compass light. On the port console fuse block I am planning to add an auxiliary cigarette lighter style power jack some LED interior lights and possibly another vhf down the road. I am considering a radar at some point too.

The idea is to take most of these items off the starter motor terminal and negative side battery terminal and put them on junction blocks somewhere that is easy to access. The fuse blocks have lots of spaces left and will remain as is.

Grant

 

[Grant Brown]

Re: Remote Battery, Perko and Junction Block

Here's what I was thinking:

 

[Silvertip]

Re: Remote Battery, Perko and Junction Block

By "junction block" I assume you mean the feeds to the fuse/breaker panels. If so, this is the way it should be and thats what the diagram for installation of the switch would show.

 

[Grant Brown]

Re: Remote Battery, Perko and Junction Block

Thanks that's what I was wondering. I did not install the Perko just moved the second battery so I have never seen a wiring diagram for it.
I was wondering if there is a standard for the "junction block" (not sure if this is the right term or not)?

Grant

 

[fishrdan]

Re: Remote Battery, Perko and Junction Block

Junction block, do you mean a terminal block?

I have one of these (not this exact model) mounted high on the transom to service all the grounds for the accessories in the stern of the boat. I grounded it to the engine block (I/O) at the battery ground location, really helped clean up the wiring in the stern of the boat.

I wouldn't use a terminal block for the +12V leads as in your diagram, it would be cluttered with all those in-line fuse holders. I'd run the + wires up to your fuse panels so the + leads are fuse protected. Well, at least that's how I'd do it........

 

[Silvertip]

Re: Remote Battery, Perko and Junction Block

That type of terminal (junction) strip is fine for small gauge wire but is not suitable at all for the high current cables that run to a battery switch since all those cables are battery cable size (or should be).

 

[fishrdan]

Re: Remote Battery, Perko and Junction Block

Correct, I took it that he was trying to remove the accessories off the battery. As in moving all the grounds to a terminal block, then grounding the terminal block to the battery. It would be more organized using a terminal block.

One of these would work for connecting the negative battery cables (3/8" or 5/16" stud) if he wanted to terminate all the accessories at 1 post. (Though I think it would be cluttered)

 

[fishrdan]

Re: Remote Battery, Perko and Junction Block

double post

 

[Grant Brown]

Re: Remote Battery, Perko and Junction Block

Correct, I took it that he was trying to remove the accessories off the battery. As in moving all the grounds to a terminal block, then grounding the terminal block to the battery. It would be more organized using a terminal block.

I'm finally getting back to this job.
I only need places to supply/ground a couple of accessories and 2 fuse boxes (one fuse box each side of the boat up front).
I did not know the correct term for the "terminal block" but that pic is what I had in mind.
Could I supply the power to the terminal block by running the switched power from the perko to the term. blocks then to the starter? I would do the same with the negative grounds from the batteries to a term. block and then to the motor ground.
I mean have them stacked on the same post on the terminal blocks? Then there would not be high current flowing through the terminal blocks, they would just be either a really good hot or ground.

Is the bilge pump supposed to be hot always (unswitched by the perko)? If so, which battery would be best?

Thanks,
Grant

 

[Silvertip]

Re: Remote Battery, Perko and Junction Block

You need to draw this out because I have the feeling you are leaving yourself open to disaster. Grounds do not need to be run back to the engine block. The negative terminal of the batter(ies) need to be tied together and then the large battery cable goes to the engine block. A ground bus should go to the negative terminal of the batteries. You also mention two fuse panels one on each side of the boat. Why? What do you intend to wire to the starter? Remember -- all cables connecting the battery negative posts to the engine, and the cables from the battery positive post to the switch MUST be battery cable size wires. Anything less than that will result in smoke and fire when you try to crank the engine. The bilge pump, if it is an automatic type, should be connected to the largest capacity deep cycle in your boat and must not go through the switch. You want it to pump water when you are not there!

 

[arks]

Re: Remote Battery, Perko and Junction Block

Grant-
I used this fuse block when adding a remote battery to my boat. It's ABYC/USCG approved and is rated for up to 4/0 wire and 750A.
In my case I only needed a positive block, but I think they also make a black (negative) model as well. They ain't cheap- about 40 bucks, BUT they are the correct part for the job.

I'm sure you're using the proper marine-rated stranded/tinned wire, right?
Make sure you also use proper ring terminals and crimpers- no short cuts.

 

[Grant Brown]

Re: Remote Battery, Perko and Junction Block

Silvertip:
OK I got you on the cable sizes and safety issues. AGAIN.
Thanks for your concern but maybe you should re-read the whole post...
Bilge goes to the deep cycle - got it.

Grant
Vancouver, BC

 

[Grant Brown]

Re: Remote Battery, Perko and Junction Block

Arks.
Like I said in an earlier post, tinned wire soldered and sealed with self sealing heat shrink tube for connections and soldered lugs...