solar panel to trickle charge batteries? - The Hull Truth

kmont97 · 03-24-2009, 04:11 PM

I have 4 batteries, 2 starting and 2 deep cycle (house) batts. There is an onboard charger which is of little to no use for me as I plan to keep my boat on a mooring. Is there a small panel that I can hook up to the batteries to charge them? Periodically I could just switch it to another battery. I'm just thinking about how I can keep them charged for the summer. I like to use it every weekend but sometimes this is not possible. I just don't want to be stuck w/ a dead battery when I want to use it.

bajadan · 03-24-2009, 04:49 PM

Small 5-20 watt solar panels work great to keep the boat batteries maintained with a trickle charge. I have one on my boat now.

The only possible downside is, if you do not have some sort of controller that will automatically shut the charging off when the battery is full, you risk damaging your battery. Go with a very small watt charger if you do not use a controller.

kmont97 · 03-24-2009, 05:17 PM

What brand is yours? Do you have a controller? Thanks for your help.

bajadan · 03-24-2009, 06:06 PM

Brand is not important. Most brands of solar panels are very good.. Many of the solar panel companies have been bought out or merged in the last few years. Getting the right size/watt panel is important....

I am not using a controller now on my boat solar panel, but should. My boat is in the back yard so I can go out daily and move the charger to a different battery. If you can find a solar panel with a controller, then the size of the panel is not important.

I just goggled 20 watt solar panels with built-in charges and a few came up. Also found a 10 amp controller for under $40 that should work fine with a boat size solar panel.. A 10 amp. controller should handle up to a 100 watt system. Google "Sunsei Solar Panel 10 Amp Charger Controller". There are a ton of choices out there now...

I am on my 5th solar system. I have a very large system with a huge very advanced controller on my RV for dry camping... I am not an electrical expert!!! So if someone finds I am giving bad info please correct me. All of my knowledge about solar systems was learned from doing it wrong too many times...

Tar Heel Waterman · 03-24-2009, 06:16 PM

What kinds of issues have you had before bajadan? I've seen some of these panels and wondered how they work. Does it need to be disconnected during boat use or can it remain fixed on the t top of a smaller craft?

bajadan · 03-24-2009, 06:46 PM

On a moving boat, the big issue would be how fragile the solar panel is. I built a box around my small panel to give it more support, however, the face is still glass and will break easily if struck with a hard object. I have had one get knocked over in a strong wind and break. They do make flexible solar panels like our military uses, however, I can not justify the cost for such a low watt output.

You can leave it connected while running..

I do not leave mine on the boat when running. I do not have a good safe way to permanently mount it.

I also use this small solar panel to charge other 12 volt batteries as needed, very handy to have around the house. Actually I have two boats in the back yard with batteries to keep up, plus some other extra 12 volt batteries I keep in the garage.

There are three components to a solar system. The heart of the system is the controller. The controller size limits how many panels (2nd part) or how much total wattage/amps you can connect to it. The third part is the batteries, which is limited only by your budget.

In theory, if you had a big enough controller, you could run an entire city on solar... just keep adding solar panels and battery storage capacity to meet the electrical needs.

Most problems I have had with my RV solar panels revolves around getting the right combination of panels and batteries. When I was traveling to Baja, it was not much of an issue since the sun is always shinning. However, dry camping here in Washington state., well lets just say we do not always have sunshine every day and the solar system is not as productive here.

jmardo · 03-25-2009, 06:05 AM

Check these out... http://isaveenergy.com/bsp30-12-lsssolarpanel.aspx a little pricy but if you have the room on top of a t-top this will work great. Just install the system and forget it. Since you're charging 4 batterys you could even go with the 40watt model. I've used several solar setups and this is the best. You should use a solar controller and connect the batterys together with battery combiner and you are all set.

I currently use this panel to charge 3 AGM batts while my boat is on a mooring from late april to Oct, my batts are always at 13.4-13.8 when I get on-board. Plus, this is a supplement while using the stereo on a long drift, not to mention the peace of mind when you can't get to the boat to run it on a weekend.

joe

BURGERflipper · 12-07-2010, 01:42 PM

I don't want to come off as a spammer or troll or other indignant online menace but.

I found this post while I was looking for how to mount my solar battery minder for my 16ft V hull boat. I ended up mounting it on the windshield\splash shield, not the best place but it keeps the rain off of the thing and only gets light spray from the bow so far no issues. (its been about a month but I haven't done to much boating because of the weather

)

Anywho, here is what I found a for my boat, it only has 2 batteries one for lights the other for cranking.

http://www.12volt-travel.com/solar-b...r-p-13127.html

My boat.

Only thing that I noticed was that the plastic has a glare in the sunlight =(, even being under the overhang.