Battery Bank / Starter Battery Question for the Group

[n624ma]

I have a question for all of you.
Has any one else eliminated their Starter battery and the 1-2-Both Switch?

Two years ago I decided to simplify the power supply side of the boat, this resulted in dire predictions of being stranded off a lee shore with a hurricane approaching and being unable to start the engine, or something like that.

Cynosure has the following setup:
            3 Group 27 lead acids wired in parallel as the only battery bank
                          (they came with the boat and will become 4 GC-2's when they die)
            The alternator wired directly to the bank
            An On-Off battery switch at the electrical panel
            A Waeco CF-50 refrigerator Cooler
            An 85 watt solar panel
            Raymarine C-80 with GPS, Radar, Autopilot, Wind, Depth and Knotmeter

We are on a mooring or anchored out and typically spend several days on the boat each week during the summer.
We have never had an issue with starting and the Nav electronics don't drop out when the engine is started.

Has anyone else done this or thought about it?

[Stu Jackson]

Joseph, that sounds like a good setup.  The solar panel is perfect for your mooring arrangement and keeps the bank up, which is necessary for battery health and longevity.  "Losing" the 1-2-B switch was not really necessary, since you could have kept it, and avoided the cost of a new switch, by simply leaving the 1-2-B and only using, say, position 1.  "Now he tells me!"

In all my years with our three battery Group 31 130 ah each house bank and a separate reserve bank, I have only had to use the reserve bank once in 15 years! I was, however, glad it was there.

If, however, you carefully monitor your house bank, it is an optional arrangement that I've seen reported to work just fine for many cruising sailors.  I would use a battery monitor, as well as regular (but not too frequent) hydrometer checks on the health of each individual battery.  Battery monitors are sometimes the last thing folks add, but actually should be one of the first.

Good question.

Your boat, your choice.  

[n624ma]

Stu,
We have a Xantrex battery monitor, and I agree with you that they are essential.

Without the monitor you not only do not know the state of the battery bank, but you have no real idea of your energy usage habits.

The On-Off switch was recycled from the starter battery setup. It is really nice when we have guests on board since you can tell them to turn the "Big Switch" to On and then flip on whatever they need to use.

This winter plans call for re-doing the switch/fuse panel with circuit breakers and using a breaker as a DC Power switch similar to the AC side.

[Stu Jackson]

This winter plans call for re-doing the switch/fuse panel with circuit breakers and using a breaker as a DC Power switch similar to the AC side.

Not sure why you'd want to.  The battery bank fuse should protect the wiring, and using a breaker instead of a simple switch doesn't make much sense to me.  What do you think you'd be "protecting?"

[n624ma]

Stu,
It's actually a space issue, by making a new panel with circuit beakers I can relocate the VHF and Stereo into the area originally used by by the 1-2-Both switch.
The battery bank has Current Limiters on everything connected to it for wiring protection.

Here is a pic of the panel I made for the last boat.

[chuck53]

The PO of our boat installed 4 - 6v batteries in series/parallel for the house and a single 12v starting battery.  Each has its own on/off switch.  I do have a separate on/off switch I can use to switch the house bank over to start the engine if needed.

[Ron Hill]

Joseph : There are other uses for a starting battery besides just to start the engine.
I also have my windlass wired into the starting battery!  That way it get some more "exercise" (of the starting battery!!)

A thought

[n624ma]

Ron,
A good use, but, "I" am the windlass on Cynosure, and you're right, it is a way to get some exercise.

In all seriousness though what I wanted to accomplish was to get the largest battery with the fewest components and the minimum of switching choices. So far it is working as planned with no problems and I wanted a wider input on the idea.

We hardly ever draw the bank down below 75% and we are not frugal with cabin lights or electronic entertainment.