wiring recommendations...

Hi, I?m looking for some advice on how to wire up my boat?s electrical components. I have an 18? Duckworth Pro Steelheader II, which is a center console boat. It currently has a 1989 Yamaha 115/80 2 stroke jet motor on it. I currently have only one battery in the boat, which the outboard is hooked to for electric start. All electrical components are currently wired to the one battery. I have an On/Off perko switch, to cut all power to all components.
I will soon be purchasing an electric start kicker motor (most likely a Yamaha T9.9), as well as 2 Cannon Mag 10 stx electric downriggers. I?ll obviously need an additional battery as well. My question has to do with wiring all of this up in the ?best? way. Would it make sense to keep the main motor connected to the existing battery, with its existing perko switch, and then setup up the kicker motor, 2nd battery, and two electric downriggers with their own perko switch? Basically, two totally independent systems? I could then keep a set of jumper cables in the boat, in the event that I would need to jump start one of the batteries. Will the two electric downriggers do ok attached to one battery (being charged by the kicker), or would you suggest two additional batteries (1 downrigger per battery)? I will be installing a circuit breaker or fuse near the battery for each downrigger.
Any other suggestions as to how best to wire this all up? I?ve seen the BEP battery distribution clusters, as well as the Perko switches with the 1, 2, both, off settings. Would I be better off with the two independent electrical systems, or something like the BEP cluster?
Thanks,
Ken

Re: wiring recommendations...

You need to rethink your plan for a number of reasons, the least of which is the fact that the auxiliary battery should be a large deep cycle since it will see the most severe use. The kicker will be operated at less than wide open throttle and with the limited output will not likely keep that battery topped off. So here is just one of several options and the least expensive, most reliable, and most versatile system you can install.

1) Install a dual (two bank) on-board charger with a minimum of 6 amps/bank so you can plug in at the dock or at the storage facility/home to fully charge both batteries and maintain them properly.
2) Install a dual battery switch (OFF, BAT 1-BOTH-BAT2). This allows every accessory, including the feed to the current fuse panel to be connected to the COM terminal on the switch. The only exception would be an automatic bilge pump that would get power from the aux battery when away from the boat.
3) Both engines get connected to the COM terminal as well.

This system then works as follows:

OFF = power from both batteries is OFF. Nothing on the boat works except for the aforementioned auto bilge pump.
BAT 1 = Either engine starts off this battery, either engine will charge it, and all accessories operate from this battery. BAT 2 is going along for the ride.
BAT 2 = Same as BAT 1 but BAT 2 is powering everything. BAT 1 is going along for the ride.
BOTH = Both batteries are placed in parallel so both start the either engine, either engine charges both batteries, and both batteries power all accessories.

So when do I use each setting? Think about it. Head to your fishing destination with the switch on BOTH if you wish. However, since you just left the dock where the on-board charger has been in action, both batteries are topped off. Since you will soon be fishing and want to prevent killing the start battery (BAT 1), set the switch to BAT 2 (AUX) and fish till you can't stand it any more. Now, if either engine fails to start on BAT 2, switch to BAT 1. Start the engine and when it is running, switch back to BAT 2 for the trip back since that battery needs the charge. It's really not that difficult. And this topic has been pounded to death and the solutions are always the same. Don't recreate a hodge-podge of electrics that are not reliable, not flexible, and simply don't work as well as they could. The dual bank charger is $100, a group size 27 deep cycle battery can be had at most farm stores for $75 and the switch is about $40.

Here is a diagram minus the feed to the current fuse panel (e.g., the "boat" electrical system)

Re: wiring recommendations...

I agree with silvertip about needing a deepcycle battery to hook your down riggers, kicker motor and any electronics. I differ in that an Off, 1, 2, Both switch is not the best choice. Mostly because you have to keep changing the switch when you change engines.
Consider one of the Add-A-Battery kits.
You turn it on, and your batteries are isolated. You can run the deepcycle completely down without ever discharging your starting battery. Then when you start your main engine, it will now charge the deep cycle too. (although not much as your main motor doesn't have a huge charge rate) all without having to change the switch from the on position.

Re: wiring recommendations...

+1 with Don ^^^

Plus a simple charger will charge BOTH batteries because as soon as the ACR sees one battery go over 13 volts it will combine the two batteries and both will be charged in parallel.

The ACR just thinks the motor is running.
The least charged battery will absorb the most charge until they are equally charged.
There is nothing for you to forget to do either.

Re: wiring recommendations...

I'm an old dummy with computers so maybe this will work. Search "continuousWave/Whaler/Reference dual battery" and read the article. I tried to post the link, but don't know how so hope this works. Anyway I used the "New" diagram except I added an on/off in the neg line so I could shut it all down. There is a little more involved when you have two engines.

I know everyone says that your engine won't charge the battery very well but My 9.9 merc pro kicker keeps mine charged. I have two elect Big Jons and two electric scotty's plus depth sounder, nav lights, fish hawk downrigger speed and temp, gauges and stuff and my kicker will keep up with it at salmon trolling speeds. You don't ever want to run both engines at the same time with your switch in the "Both" position.

Re: wiring recommendations...

It is not recommended to have an on/off switch in the negative cable. In theory its ok but since every other boat out there does not have it that way, its just a bad practice.

Most engine's outputs can be tied to each other to charge a battery so its not a blanket statement that you can't do that. basically, follow your engine's recommendations.

Re: wiring recommendations...

Your right I don't know anyone else who has a switch in the neg line. Why is it bad practice? Not recommended by who?

Most engines? Which ones exactly? I burned out the stator on my main engine hooking them together for about 10 seconds.. That's a '79 merc 115 and a 2012 pro kicker. I do know people who do this and have had no problems. Also know people who have burned out stators and regulators including me. I just mean for the OP to be careful.

Neither of my engine manuals adress this issue at all so how do I follow the engine recomendations?

Re: wiring recommendations...

Why is it bad practice? Not recommended by who?

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The ABYC for one. Here are excerpts from the E-11 standards.

Since about 99.99% of the boats are wired with the battery switch in the positive cable, it would be really confusing to someone to suddenly find one with it in the negative cable. Could cause someone to hook a battery up backwards.













The exception

Re: wiring recommendations...

Georgesalmon said:

I burned out the stator on my main engine hooking them together for about 10 seconds.. That's a '79 merc 115 and a 2012 pro kicker. I do know people who do this and have had no problems.

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Some outboards do not have regulation. If yours doesn't then that is why you have an issue. Any inboard type engine and most outboards that have regulators should be fine.

Your small motor puts out at most 6 amps and that is when its running at high RPM. Curious why you even have it connected to your charging circuit unless its for emergency use. Have you ever measured the voltage output iof your 2 charging systems when they are run independently?

Re: wiring recommendations...

In my case the 115 has a regulator from a newer engine because I didn't like the high voltage it put out with the original rectifyer only. Thanks for the ABYC info guess i should rethink how I shut everything down, maybe two switches in the pos, one on each battery. When I trun on the kicker switch I get just 12vdc, but after I start it the meter goes up to 13.5vdc, thats why I think I'm getting at least some charging (maintaining?)going on. My depth finder also has a voltmeter and it shows the same so I think my voltmeter is pretty accurate. I think the pro kicker has a 10 amp charging max of course at high rpm's. I know I'm not getting much at trolling speeds but it does seem to keep up with everything. When I'm trolling I have the nav lights on (dark or foggy of course), depth finder, downrigger speed and temp, marine radio, gauges, interior lights, and use the downriggers off and on. All my lights are LED which helps I'm sure. I also have a pro mariner two batt 8 amp on board charger. When I get home I plug it in and it only takes a couple of hours until the light comes on that says its not charging anymore just maintaining. My main engine battery is just a normal marine starting battery and my kicker is a 27 series deep cycle because that's the one I have all the house loads connected to(nearly all the time), except the bilge pumps are hard wired to the main engine battery. I can and do run both engines at the same time as long as I do not have my batt switch in "BOTH" which is nice for warming up the 4 stroke kicker.

Re: wiring recommendations...

One good reason for not putting a master shut off in the ground leg is that a short to ground in the POSITIVE side results in a live circuit which will pop the breaker (if there is one) but if it happens to be an auto reset type it will repeatedly trip and reset until it finially welds itself closed and your boat burns down. If the switch is placed right at the negative post of the battery thats not much of an issue unless you happen to have a tin (as in aluminum) hull in which case the hull will be at ground via the engine mounting bolts. You now have the same situation. If the switch is located a fair distance from the battery then the switch does no good if the short is between the switch and the battery.

Re: wiring recommendations...

glass boat in my case. I do have breakers in all the equipment but no auto reset ones. The house mains are at the battery and the engines have their own internal fuses, all other equipment is fused or breakered at the dash and/or at the equipment. I'm still not understanding this as a problem. When the switch is on its no different than any boat. When off there is a break in the neg about three feet from the batt's. any short from pos to neg anywhere is still protected by breakers and fuses no matter where it happens unless its a battery cable, right? But thats true on any boat too. I get that ABYC says not to do it and maybe no other boats do it but don't understand how its an electrical danger.

Re: wiring recommendations...

It isn't JUST about the short but WHERE the short occurs. A short in that three feet of unprotected wire, although unlikely is "possible". If it is possible it can happen. Yes - you have a manual breaker at the battery POS which would pop in that scenario. But all of the accessories can become powered if there is a ground issue -- and that issue does not mean a short to ground. There is a time and place for switching ground but a boat power system is not the place. If this were accepted methodology, your house would be wired that way as well -- and it isn't. Electronics and engine management systems often switch internal ground circuits. Look at it this way -- there is nothing wrong with what you have from a current flow perspective. However, you have +12V available to every circuit in the boat -- but current is just not flowing. Current tries to get back to the battery in any way it can. Let's assume you attempt to start your engine with the battery switch off. The engine will try to pull ground from wherever it finds it. Any device connected directly to the battery (not affected by the switch) becomes a potential ground path. In the case of an automatic bilge pump, fuel gauge, or any other such device, that path can very likely NOT carry the engine starting current and it will smoke the wire. All it takes is one thing that is not right in your system and you have a potential problem. If everything is always perfect, you are ok. How much of a risk taker you are is what's at stake.

Re: wiring recommendations...

84toyota said:

I?m looking for some advice on how to wire up my boat?s electrical components.

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I give advice about that in

Boat Electrical Circuits and Wiring Practices
continuousWave: Whaler: Reference: Boat Wiring