Guidance on keeping batteries charged

[newburyporter]

I own a 2011 Benneteau 40 with 2 friends.

We keep her on a mooring in Marion, MA.

When we bought the boat we bought a small solar panel thinking that, along with motoring would keep batteries charged.

We have found that it does not and we want to rectify the situation. I am thinking we will need a combination of wind and solar to do so on a mooring. Maybe this cost will cause us to bite the bullet and get a slip!

We have asked our marina to give us a quote but I like to research a bit myself.

400AH of house batttery (AGM). 2 200 AM batteris.
Starter battery.
Battery in bow for bow thruster.

I am sure there are many resources out there offering guidance for sizing wind and solar in combination.

Can someone:
1) Point me in the direction of a source you like and trust
&
2) If you have similar battery setup and are on a mooring, what have you done that has been successful in keeping batteries close to 100% charge?

Thanks!

Brent

 

[Caboteur]

I have a very similar setup and am on a mooring. The boat is in water from early May to mid-October. The refrigerator and anchor light (LED) are on all the time. I run the engine from mooring to sailing... two to three hundred meters; not enough to charge anything.
I use the boat extensively and cruise widely. I have two eighty five watt solar panels that keep the batteries full at all times.
My first set of lead-acid batteries lasted five full seasons plus one winter in the Bahamas. I leave the batteries in the boat in the winter and usually turn the panels on for various periods in the off-season.
I have no wind generation ans no on-board generator... I have an 80Amp Balmar with external control but do not run the engine for charging purposes.
http://beneteau.sailboatowners.com/...d=259&cat_id=1075&aid=7973&page=article&mn=31

 

[Maine Sail]

Brent,

We really need more information in order to help:

*How many Ah's per day do you use?

*Do you have refrigeration?

*Are any loads, other than bilge pumps, left on during the week or are the batteries completely OFF?

*How big is the alternator?

*Internal or external regulation?

*What is the absorption voltage of the alternator?

*How are you determining the state of charge?

*Do you have a battery monitor or other means to determine SOC other than voltage?

*How are the battery banks charged via the alternator?

*What SOC does your alt get you back to by the time you leave her on the mooring?

*How many watts is the existing solar panel?

*What solar controller are you using?

*Where does the alternator feed before it hits the house bank?

*What brand are the batteries?

*How old are the batteries?

 

[Stu Jackson]

The reason Maine Sail is asking all these questions is, indirectly, that you should do what is called an energy budget. Figure what goes out, compared to what goes in and how large your house battery bank is. This is basic electrical system design stuff, and doing a search on this or any other boating forum on "energy budget" will give you lots of reading. Or buy a book, like Charlie Wing's, and figure it out.

For most folks on moorings, solar has been determined by trial, error, expense and experience to be the better choice, compared to wind. Many have started with wind and converted to solar. Even dismantled their wind. Some because of noise, but most for ROI. The amps delivered by solar, $ for $, are much better.

Good luck.

 

[jepomer]

My boat is on a mooring. It has an electric drive and batteries. A 100 watt solar panel and well designed MPPT charge controller keeps the batteries charged for our uses.

Do the math for the energy budget like Maine Sail recommended. That is what I did to see if the setup would be practical. Two seasons on a mooring (with no shore or engine charging) in Winthrop MA have verified the calculations.