Solar charged secondary 12volt system to run accessories

[DoryLvr]

I would like to install a solar charged secondary 12v system in my 16 cruiser to run accessories and not jeapordize starting the next morning. I am thinking about mounting the second battery in one of the compartments under one of the chairs which would allow for easy wiring up to a solar panel on the roof of the cabin. I am thinking about putting in 12v cigarette lighter style receptacles for charging rechargeable lanterns, running a 12v 4 cup coffee maker and even a little 12v electric frying pan that I have run off a car before. Does anyone have thoughts, ideas, experience, lessons learned that they could share?

 

[journey on]

I take it that you want to install a separate house battery, and also install solar panels to keep the battery charged. I've had solar panels on a boat, and have a bunch of solar panels in back of the house. So, I have two comments.

First estimate the amp-hrs you will need to run the appliances you mention. At 12 Vdc, a small skillet would draw 70 amps for 700 watts. If you run that for 1/4 hr (15 min,) that's 17 amp hrs, and so forth. Appliances that depend on electric heating are power hogs. You have to size both the battery to give you all the amp-hrs you need and the solar panels to recharge the battery. This is the most important step.

That brings us to the second point. Solar panels take a lot of square footage to generate reasonable power. And for max power they have to be pointed at the sun. I installed the sailboats solar panels flat on top of the bimini, and for 5 amps at noon they were about 4' by 4'. And they weren't cheap. I probably got 15-20 amp-hrs per day.

So size your system first, then cost it out. If everything works out, go for it. After trying solar panels on the sailboat, I came to the conclusion that the second battery was a great idea, and bought a Honda generator for charging.

Boris

 

[thataway]

I agree with Boris. You will do better by adding extra battery capacity; maybe even two. The Solar pannels are expensive, and will take a lot of room.

How much charging capacity does your engine alternator put out? For example the Honda 50 only puts out 10 amps, the Suzuki 50; 18 amps. The car alternator puts out 60 plus amps. You would have to run the Honda for 5 to 6 hours to replace the usable amount of power in a Group 27 battery. (this would be about 50 amp hours). You cannot use a coffee pot or frying pan for very long.

An 80 watt solar panel (gives about 4.75 amps)--running 12 hours a day would probably not quite give you the 50 amps (because it would not have maximum sun orientation)--and would cost about $400 to $500, plus controler etc...cheaper to buy two batteries. But try it with one first and recharge at home.

You are much better off cooking with a fuel--outside with propane, inside with diesel or alcohol. Most 16 owners cook in the cockpit, so propane would work fine. You only need a few lights at night--and certainly you can recharge lanterns--but I find that LED lanterns run for 30 to 50 hours on AA batteries (can be recharged at home).