Any Solar installs on A27's ?

[11kolive]

As we get closer to selling our Grand Banks and finding our A-27, I am wondering if there are any solar installs that folks have done. We are working on figuring out how to increase time on the hook and the two biggest draws we would have are my wife's cpap machine and refrigeration. So I am looking at solar installs and battery bank needs to supplement the alternator.

This will of course necessitate an appropriate sized battery bank and space questions too.

Any thoughts and input will be happily considered.

Keith

[Jay Knoll]

Hi Keith

Check out my A27 FC refit thread, near the end you'll see the solar setup on my hardtop. 4 55 watt (I believe) panels going to 2 4Ds wired in parallel (separate isolated starting battery). We have 12v refrigeration on board. I ran the fridge at the dock for about a month after I installed it, strictly on the solar, the system was rock solid.

Jay

[DesertAlbin736]

It's always about amp-hours, especially on a small boat. As with everything in boating it's about compromises bewteen the generation/storage side and demand/consumption side. Every bit you can reduce consumption is a bit less you have to increase generation/storage capacity. Converting lighting to LEDs is a first step. That's what we did with anchor lights and all cabin lights including even our small G4 size reading lamps except those that are only used intermittantly like the head compartment. I didn't bother converting the running lights, since by definition they're mostly only going to be on when the engine is running.

Larger battery bank and at least a 100 amp alternator is a start. We have a 20 watt solar panel on our hard top roof that I can switch on or off as needed, and run it through a charge controller for our AGM batteries. It's mostly for trickle charging the batteries since we don't have access to 110V plug in where we keep the boat stored on the trailer. With a pair of 90 amp hour dual purpose Group 27 AGMs wired in paralallel (plus an identical start battery) I've got conservatively 90 amp hours capacity in the house bank while on the hook before they're discharged to 50%. The only refrigeration we have is well a insulated Coleman cooler that can be plugged into 12V cigarette lighter socket, but for the most part we use ice and only plug in the 12V when the engine is running. It's best not to run the engine in neutral & light load just to charge the batteries if possible. The solar panel output is about +/-15 volts going into the controller and regulated to 13.4 for a float charge, which would be about 1.5 amps at peak. Say it averages about 1 amp from dawn to dusk, maybe 10 to 12 amp hours per day. That's enough to power about 1 incandescent light bulb equal to as many hours as the sun shines during the day. If you're going to spend a lot of time at anchor you're going to have to think like a sailboater and be absolutely anal about conserving power demand.

The cpap machine you can't get away from using & would be highest priority load. I don't know anything about cpap machines or what kind of wattage they draw but assume you'd be running it off an inverter. Some sort of small motor or compressor type thing? For refrigeration minimizing the amount of items needing refrigeration would help. Whatever type of refrigeration used making it more efficient by adding insulation and keeping it in shade would help. Engine driven, 12V, or combo engine/12V holding plate system would probably be your best best bet if a)money is no object, and b) the setup you find or can install in the A27 you end up purchasing. In any case figure on a 5 amp draw & at least 200 amp hour battery bank with a large enough solar panel (or an auxiliary genset) capable of supplying at least an extra 50 to 60 amp hours per day. I know a lot of A25's have front loading 12V fridges built into the port side of the cockpit between the bench seat and the door to the main cabin, but ours doesn't. We rely on coolers and block ice whenever we can get it. We have two coolers, one is a regular "5 day" cooler, the other the above mentioned 12V Coleman cooler. The Coleman came with the boat, and some of that type of coolers on the market are quite expensive. When we're out for just a weekend we use one or the other of those coolers. On extended cruises we use both, as we did this summer spending 45 consecutive days afloat.

http://www.westmarine.com/WestAdvisor/S ... -Your-Boat



Here's a West Marine primer on refrigeration.

[11kolive]

No doubt about it that amp hours rule in any of these discussions. The cpap draws 3.75 amps. So...I think I am looking to enlarge a battery bank for the power I know we will need. I know this can be a huge can of worms to open based on other threads I have read so I am taking the time to plan it out right the first time...I hope. We currently have 6 6v Trojan batteries as our house bank, but I am not sure the A27 has that kind is space for them. Switching to led's is a given and miserly use and monitoring is our mojo.

Adding solar is going to be new for us and we are learning a lot to get this setup properly. Enclosed is a photo of the cpap machine.

IMG_4237.JPG

Keith

[Beta Don]

I would bet you that 3.75 amps is a worst case scenario and the actual draw when in normal use will be about half that. We traveled on our A27 with electric refrigeration, four 6 volt golf cart batteries and a pair of 160 watt solar panels on the roof. The refrigeration used the lions share of the power, much more than the CPAP machine. My wifes is a Devilbiss Intellipap DV54D with heated humidifier - The humidifier does not function on 12 volts, but on the boat with the fresh marine air, she never missed the humidifier . . . . unless the A/C was running and then the CPAP reverts to it's normal 120 volts. I think it's average draw on 12 volts was right around 1.5 amps

Don

[tego]

Keith, I read 24 volts and 3.75 Amps on your data plate. That'll require a separate battery setup for the 24 volts won't it? Ben

[11kolive]

IMG_4238.JPG

The unit had a 110 plug in for it. I will post a photo of it's label too.
The power supply unit says 1.5 amps @ 110 v. And puts out 3.75 DC
Keith

[DesertAlbin736]

Keith, I read 24 volts and 3.75 Amps on your data plate. That'll require a separate battery setup for the 24 volts won't it? Ben

Easily solved by plugging the AC adapter into a 12V DC to 110 AC inverter. Data plate says the AC adapter is rated at 90 watts. 90 watts / 12V = 7.5 DC amps, not counting losses involved in inverting 12V DC to 110V AC & the power supply rectifying output to back to DC at 24V. Let's say 9 amps DC equivalent @ 12V for round numbers accounting for conversion losses. Those 9 amps at 12V going into the inverter is what would rack up the amp hours on the 12V batteries. Smart idea to have a house bank of four or six 6V golf cart batteries in series-parallel if you want to stay with FLA's, or other high capacity deep cycle batts. All a matter of available mounting space in the boat and depth of your pocketbook.

For solar panels something like this might do the trick, 160 watt, 9 amp output, roughly 5 foot by 2 foot size panel could fit on an extended hard top or forward cabin roof. Capacity can be doubled by adding a 2nd panel.

202323_solar.jpg

http://www.defender.com/product3.jsp?pa ... id=3070027

DSCN2057 (1280x960).jpg

These flexible panels would be better to accommodate a curved surface, but are much more costly.

202232_1solarflex.jpg

http://www.defender.com/product3.jsp?pa ... id=2485729

[obertra9]

I use a CPAP for about 10 anchor nights each year. I have a both a 100 watt inverter and a small inverter that plugs into a cigarette lighter. Both work fine and the 2 6volt house batteries when fully charged during the day have plenty of capacity for the night. But I do not have a refrig

[11kolive]

DesertAlbin.

What you have suggested is what I have been thinking. We currently use our 6-6v Trojan golf cart battery bank with a Xantrex inverter for 110v power and have been thinking of going the same/similar way with the addition of 2-240 watt panels on the hardtop. One area of concern is where to locate the batteries and how to deal with any excess power from the solar cells.

[Jeremyvmd]

you will need to set up the system with a solar controller which will limit the power allowed into the system. basically once the batteries are fully charged the controller will disconnect the power going from the panels to the system. A diversion controller might not be a bad idea as it can be plumbed into a HW tank - can get some hot water without needed 120v power...
https://www.emarineinc.com/categories/solar-controllers

[11kolive]

Jeremyvmd,

Thanks! This is the info I was looking for.

[Beta Don]

Easily solved by plugging the AC adapter into a 12V DC to 110 AC inverter. Data plate says the AC adapter is rated at 90 watts. 90 watts / 12V = 7.5 DC amps, not counting losses involved in inverting 12V DC to 110V AC & the power supply rectifying output to back to DC at 24V. Let's say 9 amps DC equivalent @ 12V for round numbers accounting for conversion losses. Those 9 amps at 12V going into the inverter is what would rack up the amp hours on the 12V batteries.

All true - If that particular CPAP really does consume 90 watts, I think I'd look into replacing it with a more efficient one. Carolyn's runs directly off any 12 volt supply (negating the need for the efficiency losses wasted using an inverter) and hers really does use only 1.5 to 2 amps at 12 volts - A much better solution than using 9 amps if you want extended time on the hook

Don

[Hobbit]

We are working on figuring out how to increase time on the hook and the two biggest draws we would have are my wife's cpap machine and refrigeration.

Hope this helps.


Probably 25 years ago we bought a Dometic 12v, 110v, LP cooler. It is not a piezo cooler, it is an absorption refrigerator like the kind installed in RV's.

I thought they were no longer available, but I see a company called http://www.propanecooler.com has a similar design on line.

It gets MUCH colder than a piezo cooler which will only lower the temperature about 40 degrees from ambient. If it is cranked to the lowest setting it will freeze whatever is placed against the cooling plate on an 80 degree ambient day.

I keep it permanently plugged into 110 and have the 12v run to a switched plug. When I leave the dock I turn on the 12v. I believe it uses 2 separate heating elements, one for 110 and 1 for 12v. A couple hours of cruising a day keep the batteries up for use all day. At night I switch it off just before we retire. The coldest items next to the plate keep everything cold overnight. For extended operation without juice I screw on a 1 pound LP tank which I carry in a mesh bag hung on the transom. We only attach the tank while using LP and only when we are present to smell any leaks. The rest of the time it is outside the gunnel.

The heat generated by the cooling sources are minimal, maybe 105 degrees with your hand laying directly on the exhaust.

Of course you need to use some common sense and only use the LP gas when the cooler is on the open deck (ours is always in the open cockpit under the helm bench seat), only put a bottle on it when you are using LP and are present, and probably not a good idea in a gasoline powered vessel.

We always have cold groceries and actually have left chicken legs for crab bait frozen in it for weeks.

Hobbit.

[11kolive]

Beta Don, what is the brand and model of your wife's cpap that runs on 12v? I am looking at power supply accessories from the company that makes my wife's machine but would be very interested in reading about the one you guys have!

Keith