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kaelc



Joined: 19 Jul 2017
Posts: 411
City/Region: Saanich
State or Province: BC
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: Island Magic
Photos: Stil-Afloat
PostPosted: Thu Aug 22, 2019 5:22 pm    Post subject: Re: Solar Reply with quote

knewlin wrote:
We use a Mohoo 100W fold-able panel.
We run a small Engel freezer for cocktail ice and to freeze ice blocks for the Yeti. I wanted a portable panel so we could anchor in the shade and extend out to the sun. So far, so good. The only time we have run the batteries down was during a summer in the SJI with smoke filled skies.


Thanks for this! What size Engel do you use and how long does it take to produce a block of ice. Do you think 200W should run the Engel and a few other things?
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Micahbigsur@msn.com



Joined: 27 May 2019
Posts: 484
City/Region: Big Sur
State or Province: CA
C-Dory Year: 2003
C-Dory Model: 25 Cruiser
Vessel Name: Sierra
Photos: Sierra
PostPosted: Fri Aug 23, 2019 12:11 am    Post subject: Reply with quote

Most of the Engels (We have 3 as we keep downsizing our boats) run at about 2.5 amps per hour, they will freeze a little ice in a few hours if already cold. We love them to keep things frozen and out of the fridge.
You can put together a very simple to wire up, thin lightweight100 watt panel with a 15 amp MPPT controller from Amazon close to your price range that is probably about minimum to run your boat at anchor for a couple of days without your motor or a generator. Next time you change batteries if you can move up to at least group 27s, the 31s I have are probably the max on these boats without a lot of hassle. The new panels come with connectors that you can buy extensions for that with a fuse holder near the battery make it near plug and play. Don't be afraid to use marine grade crimp connectors, they are easy and almost bullet proof. I have found that our last 2 boats systems between 300 and 400 watts will run the whole boat basically for ever off the dock
Good luck!

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Micah Curtis and Dana, RN
2003 C-dory 25 Sierra, 200, 9.9 and 2.5 Suzukis
2012 R25 SC Sequoia (2015-2018)
1978 Folkes 38 SV Audacious (2006-2015)
Micah, KJ6GUF, Dana, KJ6GXG
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jennykatz



Joined: 15 Dec 2003
Posts: 1678
City/Region: naples
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 23 Venture
Vessel Name: Little Treasurer
Photos: Jennykatz
PostPosted: Fri Aug 23, 2019 8:47 am    Post subject: solar Reply with quote

We just ordered solar for our home in SW Fl. So bye bye Elec bills to FPL but now bills to the Solar company which will be the same . Part of the enticements was the 30% Federal tax credit but also it gives you an inverter to use when FPL goes out and also a 1800 watt solar generator .I'm looking into upgrading it so hopefully getting one that will run my RV AC unit 9200 BTU . I will keep you all up to date

See some of you at the Mississippi Gathering JIm

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retired 8/08 from UAL, still working pt tm
Duck c-22 cruiser sold 6/23/08
06 Venture Cruiser with merc115CT
00 cd16 cruiser honda 40 sold 3/12
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DavidM



Joined: 24 Dec 2017
Posts: 196
City/Region: Punta Gorda
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
PostPosted: Fri Aug 23, 2019 9:20 am    Post subject: Re: solar Reply with quote

jennykatz wrote:
We just ordered solar for our home in SW Fl. So bye bye Elec bills to FPL but now bills to the Solar company which will be the same . Part of the enticements was the 30% Federal tax credit but also it gives you an inverter to use when FPL goes out and also a 1800 watt solar generator .I'm looking into upgrading it so hopefully getting one that will run my RV AC unit 9200 BTU . I will keep you all up to date

See some of you at the Mississippi Gathering JIm


It will take a LOT of solar panels to run your RV's AC unit. A 9,200 btu/hr unit pulls about 1,500 watts. And if you want to run it after the sun goes down, it will also take a LOT of batteries and even more solar panels to recharge them the next day. I doubt if your RV has enough roof area for all those panels.

David
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Micahbigsur@msn.com



Joined: 27 May 2019
Posts: 484
City/Region: Big Sur
State or Province: CA
C-Dory Year: 2003
C-Dory Model: 25 Cruiser
Vessel Name: Sierra
Photos: Sierra
PostPosted: Fri Aug 23, 2019 1:01 pm    Post subject: Reply with quote

Solar and refrigeration are hard enough on a small boat, air conditioning with just batteries and solar is pretty much impossible.
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thataway



Joined: 02 Nov 2003
Posts: 20778
City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
PostPosted: Fri Aug 23, 2019 2:47 pm    Post subject: Reply with quote

The battery load of the AC will be about 150 amps at 12 volts. This means for one hour of AC you will need 300 amp hours of usable battery. OR 6 Golf cart (series parallel) or 6 group 31 batteries. That weight would be in the nearly 500#--for one hour! The solar panels to do that charge (~5.5 amp hours per 100 watt 12 volt panel: about 2500 watts of solar panels... It is not going to happen.
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Thataway
Thataway (Ex Seaweed) 2007 25 C Dory May 2018 to Oct. 2021
Thisaway 2006 22' CDory November 2011 to May 2018
Caracal 18 140 Suzuki 2007 to present
Thataway TomCat 255 150 Suzukis June 2006 thru August 2011
C Pelican; 1992, 22 Cruiser, 2002 thru 2006
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Home port: Pensacola FL
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jennykatz



Joined: 15 Dec 2003
Posts: 1678
City/Region: naples
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 23 Venture
Vessel Name: Little Treasurer
Photos: Jennykatz
PostPosted: Tue Aug 27, 2019 9:08 am    Post subject: solar Reply with quote

I should have explained what I wanted to do with the solar generator I know it would not power my AC for a long time (overnight )
My friend who has a Cutwater 24 has 4 group 27 batteries(system comes with 2 AGM batteries 230 amp hours )so 6 group 27's and we were wondering if we could use the solar generator to get his mermaid AC system to get his boat cool for an hour trip and then an hour trip back from our Cruise club island that we own here in Naples
Then if it works on his boat try it on mine with upgrade batteries ??
Also thinking of upgrading solar generator to 2500 watts or more depending on cost $$
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DavidM



Joined: 24 Dec 2017
Posts: 196
City/Region: Punta Gorda
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
PostPosted: Tue Aug 27, 2019 9:22 am    Post subject: Reply with quote

Well, here is the physics/math answer to your question:

Group 27s whether FLA or AGMs typically store 75 AHs of power each. So 6*75= 450 AHs. But discharging below 50% reduces battery life so you should not use more than 225 AHs. 225*12= 2,700 watt hours available in that case.

Your friend has a 12,000 BTU/hr A/C system as I recall. These typically draw 12 amps or 120*12= 2,440 watts. If run continuously and you will if you are just cooling down, then you can power your A/C for about an hour.

Then it will take at least 2,700 watt hours to recharge those batteries fully for the next time. Solar panels generally can produce 4 times their wattage rating in watt hours for a sunny day. So it will take about 700 watts of panels to recharge them.

If you want to run the A/C all night which will probably be at 50% duty cycle then it will take about 4-5 times the battery capacity and 4-5 times the solar panel wattage to do that.

David
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DavidM



Joined: 24 Dec 2017
Posts: 196
City/Region: Punta Gorda
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
PostPosted: Tue Aug 27, 2019 10:41 am    Post subject: Reply with quote

Whoops, a little bad math above Crying or Very sad

The A/C will draw 1,440 watts, not 2,440. So you can power the A/C for a bit less than two hours and it will take 2-3 times the current battery capacity to run all night and 2-3 times as much solar to recharge them.

David
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jennykatz



Joined: 15 Dec 2003
Posts: 1678
City/Region: naples
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 23 Venture
Vessel Name: Little Treasurer
Photos: Jennykatz
PostPosted: Wed Aug 28, 2019 8:58 am    Post subject: electric Reply with quote

Yes I think this is doable running the AC for 2 hour trip there and back on batteries and Solar and engine running Thanks
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