Portable Solar Panels

[Sea Scamp]

Hi
I no nothing about solar panels. and need some help,
At this stage I only have 3 batteries, 1 deep cycle up the front (dedicated bow thruster) , another deep cycle house battery (runs WEACO and lights etc. And 1 normal battery for the engine.
The house and crank batteries are joined by a two way isolation switch, marked 1-off-2-both. I have that bit sussed.
I do not no if the bow thruster battery is connected yet, it has it's own isolation switch on it.

There is a small solar panel already hooked up to the crank battery, it go's through a BP panel thing.

Anyhow I want to hook up my 120w portable panel to the house battery & maybe even another 120w panel on the opposite side of the boat, to catch more sun rays when the boat swings.

Can I just hook both the alligator clips onto the battery terminals or do they have to be wired into the BP thing first

I don't want to cook anything, it is only going to be temporarily there, maybe for a month or so


Cheers

Any input will be much appreciated


Shane & Tracey

[onestepcsy37]

Solar panel goes direct to the battery posts, although you may want to add a small solar controller between the panel and the battery if overcharging is a possibilty.

[Paul Elliott]

A 120W panel will probably overcharge a typical battery unless you use a controller. If you are there to monitor the battery voltage you can get away with a direct connection, but if you leave it unattended I would definitely get a controller. You don't need a fancy MPPT one -- even a cheap controller will protect the battery.

[onestepcsy37]

Paul is correct. Didn't notice it is 120 watts. Buy a simple PWM controller that can handle up to 10 amps. The two wires from the panel go to the controller. Then run two wires from the controller direct to the battery.

Make sure you observe polarity. Plus to plus and minus to minus.
Use a large wire size. I have a 130 watt panel with about a 12 foot run from panel to battery and I am using 10 guage wire.
Check the water level in the battery regularly.

[Sea Scamp]

Thanks Guys that was great.

There is a little black box on the back of the solar panel, that the wires come out of, is that a built in controller or something else. it has got a couple of little green flashing lights on it.

Thanks

[Paul Elliott]

Originally Posted by Sea Scamp

Thanks Guys that was great.

There is a little black box on the back of the solar panel, that the wires come out of, is that a built in controller or something else. it has got a couple of little green flashing lights on it.

Thanks

Tell us about this panel (brand, model #). Normally the black box only contains screw terminals or wires, but since it has flashing lights it might be some sort of controller.

[Sea Scamp]

Hi Paul
I bought the panels on Ebay, they are 129w and, they are in two halves and fold up to form a case with handles on it, probally really meant for camping, but I have hung them over the rail, just to make do, as I have only just bought the boat, and are still in the measuring out and where to put things stag,

I am at work at the moment so can't really tell you much more about the box on the back or even brand of panels,

Is there such thing as a marine solar panel installer , or do we just go on what the bloke anchored beside us says,

[SURV69]

I'm sorry, but it sounds like you know almost nothing about solar panel and the BP box.

Unless you got all this stuff used, there should be some information about the various items ... like the BP box. is the stuff 12 volt, 24 volt or what?

As far as hooking a solar panel directly to a battery, even a 5 watt could cause problems. A 12 volt panel pushes almost 18 volts.

I don't know much about solar panels, but help the posters help you by giving some usable information,

[onestepcsy37]

Solar energy, boatwise, can be pretty simple, although some tend to make all things difficult.

Tbe basic setup is a solar panel wired to a controller wired to a battery bank. Its possible, although not common, to have a controller built into the panel frame, which might make your install even easier - just run the wires directly to the battery.

Better come clean with us and tell us the make and model and where you got it so we can find out if you have the controller too.

I bought my setup maybe five years ago when prices were higher. Kyocera 130 watt panel, $400, and Morningstar PWM controller $100. It has been running flawlessly, never serviced, since then. Thats the real beauty of solar power.

[Paul Elliott]

Is this the panel?
100W 2X50W Poly Portable Folding Solar Panel for 12V Battery Charger RV Boat | eBay


If so, this is for a 12V system and there appears to be a controller. They don't provide much information, but it looks like you can connect it directly to your batteries. I notice that the controller is not weatherproof, so be aware of that.

To complicate things, this controller is probably (?) set for automotive flooded lead-acid batteries. For many boats this will be perfect, but if you have AGM batteries you might overcharge them with the standard settings. Some controllers can be adjusted for different battery types, but I have no idea about this one.

If you have a different panel then all bets are off.

[Pete7]

in addition to a couple of fixed panels I also have a folding portable 60w panel and very useful it is too. The panel connects to a Bulgin waterproof connector mounted under the spray hood. From there the HD wiring connects to the Neg and Pos bus bars via the PWM control box and in line fuses. So the all the panels are permanently charging the batteries even when the battery master switches are off, normally when away from the boat. A 15ft lead on the portable panel means I can position it anywhere in the middle of the boat and move it quickly as the sun moves during the day.

A decent PWM solar panel controller isn't expensive and will look after the batteries in your absence. Avoid the cheap ones though, whilst they may be labelled as PWM they could easily just be an on off switch which are dreadfully wasteful of solar energy.

http://www.force4.co.uk/department/e...l#.VeNKlvlViko

I know you said this is only temporary, but croc clips on a battery are not the way to go. Wire the panel in via a PWM properly and don't skimp on the wires, heavier tinned wire have less losses or problems with corrosion.

Pete

[Paul Elliott]

Originally Posted by Pete7

A decent PWM solar panel controller isn't expensive and will look after the batteries in your absence. Avoid the cheap ones though, whilst they may be labelled as PWM they could easily just be an on off switch which are dreadfully wasteful of solar energy.

I think the PWM controllers are perhaps 10% better than the older on/off controllers. They are better, but not spectacularly so. MPPT is the next step up, probably another 10% improvement. In a heavy-use case these efficiency improvements can matter a lot, but they aren't that important in a trickle-charge application since once the battery is charged you will be discarding much of the panel's output anyway.

[Sea Scamp]

Hi

Thanks every one

Yes Paul Elliot my panels look like the one in your picture, I bought them on Ebay about 4-5 years ago, they are 120w and have been in my shed up until now, they do not have any brand labelling on them, so that's as clean as I can come on the brand of them "onestepcsy37".

I have read all of the post and much appreciate all the info in them, I am a merchant seaman and are currently in the middle of the Indian Ocean, so I can not run down to the marina and have look or even post a pick.

The boat has very limited power supplies as you now no, and also some refrigeration issues, that's why I want to hook up the 120w solar panels to my batteries so as I can run the little 60lt WEACO until I get the U-tectic fridge sorted,

Once again thank you for all the input, I now no I need a controller and good heavy tinned wire plus get rid of the alligator clips as well.

Thanks Everyone



P.S SURV69 my first line states that I no nothing about solar panels, so no need to be sorry.
Shane & Tracey

[Paul Elliott]

Actually, you *don't* need a controller. The panels include one. You should be able to hook this directly to your batteries. I would connect them through a circuit breaker or fuse though, just to be safe.

[Sea Scamp]

Thanks Paul

Can I fit a good quality controller, that will take several panels, and still run the panels that are fitted with a built in controller through the a second good quality controller.


Cheers