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Dual Batt Switch

Nhodges1

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Hi, Can someone give me a drawing/ wiring diagram of a twin engine, dual Batt and switch, somebody rewired tis thing and its all screwed up, currently has three Batts.
Thanks in advance
 
See attached.

dual-battery-boat-wiring-diagram.jpg

Run #8 AWG (or heavier) from Battery # 2 to the fuse panel on your console. Fuse that wire right off the battery. There are many videos and write ups on the Internet on how to do this properly.
 
both engines have alternators? id get rid of the 1 2 BOTH OFF switch and use one of the many solid-state automatic charging systems. You can use one battery as starting battery for both engines and charge it from engine 1 use the other two as house batteries that get charged up by engine 2. Many ways to do this.
Ultimately your goal is to have all the batteries bet fully charged while the engines run but save the starting battery for starting only. Blue sea systems makes a nice setup. you may actually want to add more batteries especially if you like to hang on the hook and run the lights and stereo and computer and tv all evening. your house bank needs to be big enough to handle everything yet not discharge more than 30 percent for safety
 
Hi, Can someone give me a drawing/ wiring diagram of a twin engine, dual Batt and switch, somebody rewired tis thing and its all screwed up, currently has three Batts.
Thanks in advance

Here is a very simple but effective way to cable your batteries to your MBSS (main battery selector switch).
Minus the Blue Sea 7622 ML ACR, it requires manual battery management.... yet it is simple to understand and manage your battery banks with.

This is a schematic for dual stations.
If single station boat, pay no attention to the upper station portion.


Dual helms dual engines  w ACR.jpg
 
What Rick shows is overly complex. The new way is to build the system with ACR and delete the battery switches.
Both engines start and run on the "start bank" but will charge up the "House bank" while running. The ACR ensures that the start bank gets charged up by bleeding off excess charge amps to it from the house bank. In emergency, like if the start bank poops out for any reason, your ACR will automatically parallel the house batteries so that you will be able to start the engines.
The 1,2,BOTH, OFF switches are cheap and dirty solution that manufacturers throw on to solve this charging problem. I don't use them at all. The new way is far better. Does not require you to worry about what position the switches are
 
What Rick shows is overly complex. The new way is to build the system with ACR and delete the battery switches.
Both engines start and run on the "start bank" but will charge up the "House bank" while running. The ACR ensures that the start bank gets charged up by bleeding off excess charge amps to it from the house bank. In emergency, like if the start bank poops out for any reason, your ACR will automatically parallel the house batteries so that you will be able to start the engines.
The 1,2,BOTH, OFF switches are cheap and dirty solution that manufacturers throw on to solve this charging problem. I don't use them at all. The new way is far better. Does not require you to worry about what position the switches are

In many cases, twin engine boats that are under 34 feet or so, will use the Stbd side engine batt bank for the house loads.
This is because the house loads are derived from the Stbd engine common interface. In other words, the Stbd engine batt bank (via the hull harness interface) provides house load power.


If you want to crank both engines from the Port side batt bank, and yet keep house loads separated from the Stbd engine side, you would need to re-wire the way in which house loads received their power. I fail to see how my schematic creates a more complicated scenario compared to doing all of that!
Now.... if you incorporate the BlueSea 7622 ML 500 Amp ACR, you can make this happen without the need to change anything re; the Stbd side batt bank and house load interface.

KIS.... keep it simple..... and owner comprehensible.
 
Usual load of old-timer BS from you. You complicate what doesn't need complicating and I'm sad to see that you can't see that.
 
Usual load of old-timer BS from you. You complicate what doesn't need complicating and I'm sad to see that you can't see that.

I am sad to see that you do not understand that we make suggestions only...... and that no one is holding a gun to the OP's head.
The OP's are free to do as they wish and to make their own decisions.


So I have an honest question for you:
Would you be willing to draft up a schematic for the OP........ one up that shows the OP how to separate his house loads from his Stbd engine side and then create this more simplistic idea that you prefer to see?

Do this, and the OP can then decide upon which system he wants to create!

Here are some icons that you can use:

Icons for 12 vdc wiring schematics.jpg
 
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Get a BEP/MARINCO dual engine 3 battery switch and follow the diagrams. Its a KISS principle switch, 2 start batteries and one house battery. Start batteries always stay charged and you can parallel all the batteries if need be. Blue sea acr is a good system. ACR and VSR systems allow proper charging of all batteries due to the house battery usually being deep cycle and of a larger amp hr.
 
2 start batteries and one house battery.

Most of us who stay on the hook overnight would not be able to sufficiently power our house loads with a single house battery.

Take that otherwise space for a second cranking battery and install multiple house bank batteries, and give yourself some AMP Hours!
 
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