Multi Battery setup question.

[perna00]

I've just got a 95' Four Winns 20' Cuddy cabin boat w/ a 5.0 OMC inboard. I plan on using it mostly to fish and sometimes to wakeboard. It has a newer battery and I still have an additional marine battery left from the last boat I had. I was thinking of putting in an additional battery box and hooking the a, b, a+b switch to the batteries so I don't have to ever worry about getting stranded. I would like to hook up an airator box and listen to the radio while fishing so I know I will have some draw on the one battery. How should I hook it up and run it? A+B when cruising and just A or B while sitting still? Let me know if this is a good idea and any feedback from people who have done it. Thanks!

 

[Silvertip]

Re: Multi Battery setup question.

Here is a diagram of how it is installed although no accessories are shown. But the logic is to connect every addessory to the COM terminal on the switch. That way you have the most versatility. You can run everything on the boat from BAT 1, BAT 2 or BOTH. You can charge BAT 1, BAT 2 or BOTH, and you can start the engine from BAT 1, BAT2 or BOTH. Doesn't get any more versatile than that.

 

[perna00]

Re: Multi Battery setup question.

Thanks for the setup pic. That is how I was picturing it in my mind. How do you run yours? Do you use only one if the boat is not running, the other to start up, and then both when running to charge it?

 

[Silvertip]

Re: Multi Battery setup question.

How you use the switch is quite simple. Which battery do you want to charge when under way. Select A, B, or Both. Which battery do you want to protect when anchored and listening to tunes and using other accessories? If you want to protect "A" from discharing you use "B". How long you sit in one spot using electronics determines how you use the switch as well. If you run from spot to spot staying in any one location just a few minutes to an hour, leave the swtich on BOTH. If you stay in one spot longer than that, switch to "B" (assuming "B" is the house battery and "A" is the starting battery). You generally want to "charge" the battery that is discharged the most. So that's the setting you use when under way. The switch is a traffic cop for electricity going into and out of the battery. You are the cops boss. Tell the juice where you want it to go. You don't need to be constantly fiddling with the switch.

 

[perna00]

Re: Multi Battery setup question.

Thanks!

 

[riptide09]

Re: Multi Battery setup question.

In general I would assume it is bad to flip the switch when the motor is running. If you ran down B listening to tunes all days you would switch to A to start but you would want to charge B. In that case I am assuming you switch to both to start and then B would get charged.

 

[Silvertip]

Re: Multi Battery setup question.

In general I would assume it is bad to flip the switch when the motor is running. If you ran down B listening to tunes all days you would switch to A to start but you would want to charge B. In that case I am assuming you switch to both to start and then B would get charged.

The current crop of battery switches are "make-before break" designs meaning the next set of contacts "make" before the existing contacts "break" so there is no issue with switching with the engine running. WARNING: You NEVER flip the switch to OFF with the engine running as that will likely cause charging system failure.