Battery, Wiring, Charging 4 O'day 22

Mike B1026 · Feb 3, 2013

Although some outboards do have charging circuits, they don't put out their "rated" amps except at full throttle. The rest of the times they are putting out much less. Usually you will be running them about ~ 1/4 throttle. Although they can help to charge a battery, most people don't run them except to get out of the marina and other short distances.

Others may be more familiar with the Oday 22 but I think an 8hp is on the big size.

kuriti · Feb 4, 2013

I too was befuddled when i started this process as most resources discuss much larger, more complex systems. I don't think charging is really necessary unless you are bringing your flat screen and blender. Here is a write up i did on another forum for my San Juan 21:

http://www.sj21class.org/phpbb2/viewtopic.php?f=16&t=171

I went on a 3 day cruise and had little impact on my battery. You can always buy a bigger battery than i did or include charging into this simple system. I agree that 8hp is alot for a 22. I have a 4hp Yamaha which is plenty, but no charging option. Enjoy!

sailingandsuch · Feb 4, 2013

I know that what you read seemed complicated and in a way it is a little bit but it's not to difficult. If you sit and write all the points down about Ahr's Amps Volts and such you can get a firm grasp on it pretty easily.

I to agree 100% that an outboard for charging your system isn't practical at all, it's pretty much useless. I was debating that when I bought my new 5hp Mercury and ending going without the alternator.

First thing you have to do is figure out how large you need your battery bank to be. THink about all the electronics and lights you will be running and approximate how long you will use them each day. Then decide how many days you want to be able to be away from the dock. You don't want to use over 50% of your battery bank before charging the system back up, thats a really good rule of thumb.

SO once you figure out how much juice your devices use and how long you will use them you will have a figreu of how many Amp Hours you use in a day. Then just size up your battery bank and get yourself some golf cart batteries or some like kurti's and wire them up in the boat.

I'm just giving you the general idea since there are many threads like you stated with more knowledgeable people posting the technical stuff.

It's really not as difficult as you imagine, I was thinking exactly how you are right now.

rgranger · Feb 4, 2013

Go solar.... it is cheaper and works while actually SAILING.

But if you do decide to get an alternator on your outboard.... look at the Tohatsu 6hp sail drive.

Maine Sail · Feb 4, 2013

#1 Your motor is pull start.

#2 A simple ON/OFF battery switch will work because you don't need a reserve or starting battery. Keep it simple you only need a single house bank...

#3 Depending upon your usage a single group 31 deep cycle battery may suffice though two group 27's may be necessary if you want to push for a few more days away.. For the longest life out of a battery you don't want to discharge much below 50% of capacity. So with a 100Ah battery you can use the capacity above 50% state of charge...

#4 The OB motor will have limited charging capability..

Questions:

Are you at a dock during the week or on a mooring?

If at a dock do you have a battery charger?

How much time away from the dock do you plan? Just weekends? A week or more?

What are your DC loads? Fans, lights, computer, iPad, cell phones, depth, VHF, anchor light etc. etc..

Have you done an energy budget to figure your usage?

sdstef · Feb 4, 2013

David S said:
I just did a search on this topic and there is a million post Maine Sail on 01/31/2012 did a wonderful "manuscript" on 1/both/2/off, which is way over my head. Does anyone recall a post or two for the newbees that in simple language, with wiring diagrams and various terms explained, to ready a small sailboat like my O'day 22 for a few days cruising? Perhaps a 6 HP / 8 HP outboard with charging abilities to begin with?

David S

when I rewired my boat, the battery shop did the math for me. I told him what I was running, stereo, no amp, two small fans, and the usual running lights. I weekend on my boat alot, no shore power, and with two group 27 deep cycle batteries I was amazed at how long they lasted between charges. I would always bring my laptop, and cell phone charged up and rarely used them anyway since I go sailing to de-stress. I would even leave the mast lite on all nite at anchor. I did change all interior lights to leds, four leds pull the same current as one of the old ones did. I did not use a blender or electric water pumps etc. just the basics. and about the wiring, 12v is straight forward, and easy. check out you tube sites etc. good luck

kenn · Feb 4, 2013

Maine Sail nails it as usual.

In our 19' boat, we just have a single 12v deep-cycle group 24 marine/RV battery. We have a VHF, depth and GPS, nav and anchor lights, cabin lights, portable radio, and occasionally a fan. All but one light are now LEDs, which saves alot of power. I may charge a laptop now and then, and we have a USB phone charger.

For most of the last 6 years, I've simply used an AC charger to top up the battery occasionally when the voltage edged below 12.0 v (we have a calibrated panel meter), and it would last for a 4-day weekend, or for a few weeks of occasional evening sails. Last year I bought a small 5W solar panel, I just leave it on the cockpit seat when we're away, and that's helped alot keeping the charge up. I'm watching the sales to maybe upsize it.

I don't have a master switch on the DC, but I do have a pretty awesome panel with 5 and 10A DC breakers. Right by the battery, I've put an automotive-type thermal breaker which will cut out at about 40 A.

The 12 Volt Bible (Ed Sherman is lead instructor for ABYC electrical courses) or Boat Electrics Simplified - either would be very helpful for a newbie.

sailingandsuch · Feb 4, 2013

You even left the mast light on all night?

I hope leave it on every night all night while at anchor. Not only is it the law but its for your safety and the safety of others.

sdstef · Feb 4, 2013

sailingandsuch said:
You even left the mast light on all night?

I hope leave it on every night all night while at anchor. Not only is it the law but its for your safety and the safety of others.

I was in a designated anchorage, so it is not the law. I was stating this for the benefit of the power consumption example only.

CaptDon01 · Feb 4, 2013

I've installed chargers on both 6 HP Tohatsu,(Nissan, Mercury), and our current outboard, a 5 HP Honda. The Tohatsu was cheaper, but only uses a single coil. The Honda is more expensive because it's first off, it's a Honda, and the Honda requires a new flywheel,(included in the kit). They use two coils and I've found the Honda delivers higher voltage at a much lower RPM, probably because of the dual coils? I don't know. The Honda amperage rating is about half of of the Tohatsu. Either chargers are fairly easy to install in less that an hour, and you would have to work really hard to hook the wires up wrong. But caution, "IF" you have any problems, Honda will not talk with you, and my dealer told me to go pound sand when the new kit came with a bad rectifier. My experience has been that they will keep up with our normal electrical load of running the autopilot, GPS, and VHF radio, and still have some left over to trickle charge the battery. But the GPS and VHF are real low consummers, and the autopilot isn't really bad either. I've switched to LED's for my running lights, and being that my boat is less than 23', and I don't anchor for the night in a channel, I've removed the factory anchor light.

Don

rgranger · Feb 4, 2013

sdstef said:
... I was stating this for the benefit of the power consumption example only.

That was obvious :neutral: