Notes on using a single battery

[mastreb]

I often run a little counter to the prevailing wisdom regarding the proper fit-out of a MacGregor, such as sticking with the stock single axle, sticking with the stock 13.75 ETEC-60 prop, and in this case, sticking with a relatively simple single-battery electrical system rather than using a separate house and starting battery with a combiner.

I don't use installed shore power, although we do have a rarely used 30 amp shore power extension cable. Thus far this has only been used for charging iPads and running fans when we were on the East coast.

I have decided to stick with an all-12V system. In San Diego, weather is such that we don't need or use a refrigerator or air-conditioner; rather we use shelf-stable food, red wine, and Ales that are all drinkable at room temperature. I'm not saying that my setup is good for all climates or tastes--I think it would not be appropriate on much of the east coast, especially in the Chesapeake and below--I'm just saying that a single battery is a real option for people who don't need high-powered AC devices.

In our three years of use with just a single battery, we've never had it die except once when I left the boat on accidentally, we've never charged it from shore power, and never had any trouble starting that wasn't my fault (such as poor ground connection, out of gas, etc.).

Because the ETEC-60 can be pull-started with a dead battery, I'm not worried about worst-case scenarios such as power being left on. It's solvable with a little effort.

I was however quite worried with the new autopilot and installed VHF that power drain would become an issue. I'm happy to report however that both run all day without killing the battery and with a small amount of powering each day (an hour or so) the battery stays topped off. I think I've got everything installed now that we'll ever need (we not big music system people) so I think I'm not going to need to do anything bigger in terms of an electrical system.

Here's how I'm setup: I use a simple Blue Heron 1+2 position switch (similar to a Perko) to control everything. I find I've always got the same set of things either on or off, so breaking things out into individual switch panels other than lighting is unnecessary. This switch is mounted at the base of the companionway ladder to the right (between the bottom of the ladder and the galley) right in the battery box, so all the power leads are very short to the battery. The Ground sides are all hooked to the battery, and the Blue Heron switches the positive terminals of every device.

Position 0: The ETEC-60 is lined up directly to the battery and is unswitched, so I can start it with the switch in the 0 position. This means I don't have to open up the cabin to leave the dock, I can raise and lower the motor from its side buttons on the hard, and the battery always charges when the motor runs. Because the ETEC has no power draw when its not running, this works fine.

Position 1 is for underway: The NMEA-2000 network, chart-plotter, autopilot, and VHF are powered in this position.

Position 2 is for in-port: The LED cabin lights, water system, 12V outlets, USB chargers, and handset chargers are powered in this position, along with the Nav and anchor lights.

Position 1+2 powers everything, and would be used for situations like night motoring or times when I'd want the VHF on in port, for example to listen to the weather band.

The important thing about this setup is that we can shut off everything we don't need with a single simple switch and it's always obvious what setting it should be in.

Thus far, in my environment, I've seen no need for a second battery, installed shore power, or complex electrical system.

[seahouse]

Hey Matt -

So how long would you guestimate you can run on your auto-helm under sail before your battery is, say, 50%?

I like your auto-helm setup.

- Brian.

[mastreb]

Hi Brian,

I'll just have to test. My estimate is that the autohelm is drawing 4amp hours. The max draw of the system is 7ah, and that would be running 100% duty cycle and full deflection, which the autopilot doesn't do. Given a 105ah marine battery, I should be able to run 20 hours or so on a full charge. But that's a big guess, and it doesn't include VHF power or the chartplotter.

What I do know is that after running for 10 hours, the engine starts right up with no issues, and it would be very rare that I sail for longer than ten hours a day.

Matt

[seahouse]

Ten hours -a totally acceptable span. Thanks.

[kurz]

Hello
I have also the "just one Battery" system. But I added solar panel. I would heartily recommend.

Of course you can hand-start the motor. But in rough seas... handstart in a hurry... please try it first to understand what I mean.

I added 2 solar panels at 50w, so I get 100w. I put it on the arch, very easy installation, no welding, no additional tubes. Photos later.

In this configuration I can run an cooling box waece cf 35, normal at 2 degrree Celsius. Put a switich that the cooler is just working with solar power, obove 13Volts. Interesting that it works good at all weather situation. Not much sun - cools more seldom, but weather is not so hot. Much sun - much power, heavy cooling. During night it warms up a little of cours, no matter for me.
All lights are in leds.

Just run the battery with autohelm etc I would not recommend. You never know how long you can use it. Especially on bad weather the autohelm runs a lot... And also in this condition you might want to start the motor, use lights...

And the battery dies likely without warnings...

First I used the waeco-coler volt switch. Even when it got off at 12.8Volt after a too long time... the bat hat no enough power to start. Not logical but real. So becouse of this I added the switch that the cooler just runs with solar power.

Means bats have their own soul, do not trust too much.

[Tomfoolery]

My boat came set up for two batteries, with a 1-2-both-off switch. I've only had one battery, as one was dead, and it's been fine without shore power, but I don't live on the battery, nor do I have an autohelm. The wimpy charger in the Honda BF50 seems to be enough to keep it up with only moderate use.

I'll use two batteries when I replace the one that's working now. I like having a backup battery. Just haven't done it. But they'll both be deep-cycle batts, as such a puny engine could start off a motorcycle battery (my last motorcycle had twice the engine this boat has, with a tiny battery), and I used to start a diesel boat on a single group 24 deep-cycle, so it would be a waste to not have the deep-cycle capability in the second battery.

But having said all that, I'm not sure I'd bother with a second battery if the switch and cabling wasn't already there. Oh, and I installed a 2-channel shore power charger, with both channels on the single battery right now, in anticipation of going to two batteries. But it would have taken the same effort to add a single battery charger, since there wasn't any charger installed (boat came with a little portable), so I used the 5+5, and plugged it into the shore power system that was already in place (done poorly, but in place).

[RobertB]

I use one battery also - at a time

We cruise in really hot humid weather where the refrigerator, fans, and even anchor lights at night are pretty necessary. I have the two deep cycle house batteries and a leftover auto battery for starting should I run the house batteries down. I found a good marine battery charger is necessary, wrecked one or two with the auto charger before I learned the lesson (and WM was glad I did!)

[Russ]

Matt, I know you operate differently than most.
I wouldn't count on pull starting that thing in an emergency. That's not the time to do it. As mentioned, Murphy's law will have it be when your anchor is dragging, winds are howling and seas are pitching. Plus, you can't pull start it if the battery is totally flat. You will need some juice for the ignition system.
Obviously your needs are met with one batt.

I really only use one battery also. But I sleep (and nap) better knowing I have a backup. Knowing if something gets left on while we are onshore and it goes completely flat, the motor will start with the key allows my worrisome mind some peace.

In your configuration, I would highly recommend a jumper pack.
This one is very interesting. It's the size of a small box of tissues, yet can jump start a truck.
http://www.amazon.com/PowerAll-PBJS1200 ... 42AFS8/ref

I'm confused why you have your battery switch wired that way. I guess it gives you peace of mind knowing only the circuits you need CAN be powered. My main switch panel has LED pilot lights to tell me what circuits are active. I shut down those not necessary and all of them when I leave the boat.

Your system obviously works well for you and might for others as well. Room temp beer and wine does not for us. I really enjoy our electric cooler and solar panel to run it.

--Russ

[kadet]

Plus, you can't pull start it if the battery is totally flat. You will need some juice for the ignition system.

Sorry but an E-TEC can. An E-TEC in the models listed as capable of being hand started (below 115hp from memory) requires no battery to hand start they can be hand started without even a battery connected.
Getting the motor down to start without power tilt then that's another question?

[Russ]

[An E-TEC in the models listed as capable of being hand started (below 115hp from memory) requires no battery to hand start they can be hand started without even a battery connected.
Getting the motor down to start without power tilt then that's another question?

What drives the ignition system? Does the hand turned alternator provide enough power to drive it?
Couldn't you start it, THEN tilt it down?

I don't know, I've heard pull starting these things isn't as easy as one would think. I would practice it.

[seahouse]

There might be a cut-out switch that prevents the engine from starting when it is tilted past a certain angle. You would need a large flat blade screwdriver to unscrew the relief valve at the back of the tilt unit (I think it's red in colour) and gravity will allow it to drop for starting. Use a wrist lanyard on the screwdriver .

Magnetos. Your lawnmower has no battery and yet starts.

[Russ]

Magnetos. Your lawnmower has no battery and yet starts.

Yea, but my lawnmower doesn't have a complicated computerized fuel injection, oil injection and ignition system. Those etecs have some fairly sophisticated electronics onboard.

If the thing will start without any power whatsoever, that's pretty cool.

Okay, google is my friend. YES, you can rope start these things with the battery disconnected.
http://www.youtube.com/watch?v=yE4gXSYvwWk&feature

Very impressive!

Okay, I still don't want to rip off the cowling in bouncing seas and try to do this. Nice to know that it can be though.

[mastreb]

So I actually did test rope starting this about six months after we bought the boat with the battery disconnected (I say test, I mean I left the boat powered on for a month on the trailer and killed the battery dead dead).

The hardest part was figuring out how to remove the cowling over the flywheel to get the rope on. Okay, I'll admit that I didn't even know I was looking at a cowling, and had to google what to do because I'd never rope started a motor before. I did one rather tentative (read wimpy) first pull, which didn't work, and then got my feet situated on the motor well, wound the rope up good, pulled it, it started, and I banged my head back into the wheel something nice.

I'm nice and fat, so I bring a lot of inertial mass to the motor starting problem. If it were ever a problem, I'd tie a bowline in the bitter end of my mainsheet, loop the pull cord handle through that, hang the mainsheet top block from the mast carrier arch, and tie a loop to the bottom block. Then stepping full weight onto the loop in the bottom block will pull the cord with a 4x advantage in speed and torque of 1/4 of your body weight. Should work pretty well.

But the ETEC fires right up. The generator on the thing is actually permanent magnets on the flywheel with a wire coil around the entire thing, so it's not a separate, visible unit like you'd normally see in a motor. According to their technical documents, the motor is generating 30V by 1/3 rotation and at that point the EMM is booted and ready to go. Apparently the generator naturally creates 54V, and the EMM controls exactly how much charging power it provides. I'd love to see a hack that lets idle speed in neutral throttle up to develop the full 27 charging amps when not moving, because I bet this thing would be competitive with a generator in terms of overall efficiency.

According to their docs, it generates 10 amps at 1000rpm, but I measured 12. Huh.

This is my first outboard motor, so I'm no expert it what makes an outboard good. But I can't imagine being happier with a motor. If I had one complaint, it's that it does drink a bit more oil than I expected. Fortunately I'm not paying for XD-100 because it only lasts 50% longer but costs 100% more.

As for dead battery with the motor up, just pull start the motor in the up position and then lower it running. The ETEC can run for up to 15 minutes without cycling water. You would want to be pulling it from the side, maybe with a block attached.

http://continuouswave.com/whaler/refere ... _e-tec.pdf

Another thing I noticed on this trip however: At 5..7 knots, there's enough aerodynamic backdraft and not enough forward wind behind the boat that the exhaust, including CO, blows into the cockpit under the helm seat. I'm easily annoyed by smells, so I draped a wet towel over the gap under the seat and set the helm seat back down over it which solved the problem. I'll be making a sunbrella cover for the area below the helm seat that I can snap in place to permanently fix the issue.

[DaveB]

All this has been mention in the Archives.
I for one and many other have given info on Solar Panels, Muti Batteries for house and starter batteries.
Go to Search and look for your info. Its there, just find it. The foundation on the Website is known to many. Using the search will give you info you need. So Search the Archives , You will have welcome yourself as one. Hey maybe Join the Club.
Dave

[Boblee]

I also would not be relying on pull starting the motor, yes I had to do it and yes I am a bit weaker than what I was 20 years ago but in this case if there hadn't been a bit of charge to assist by turning the key at the same time I would have been waiting for the solar to charge the house battery, ie after I got the access cover off without dropping anything in the water and all the wires clipped to the cover.
As it turns out the start battery was not flat, it had dirty terminals which I would have checked quicker except the battery is factory original 2006 so assumed it was dead until I noticed the sight glass.
There are too many situations at least for me to not have a second battery and I in fact have a third standby which was very handy this year because the house battery cooked eventually which was why it was flat in the situation above.
I really would not set out on anything but a day cruise with only one battery.
As to just using one swith to control all items, I presume all those items are seperately fused but there is no way I at least could operate that way as eg if anchored you need your anchor lights on and if running seperate again, daytime you need to turn all off while leaving other circuits on and if a fault develops you also need to isolate.