2 40 w solar panels

[ppelland]

I just installed to new 40 w solar panels on the mast and would like to bring the wire down directly to elm where the red master switch is. Can I connect the solar panel wires to the master switch or do I have to go direct to the batteries

 

[knotflying]

Do the panels have built in regulators? If not you need one otherwise you could eventually over charge the batteries. To answer your question I would see no harm at connecting at the battery switch, but before the switch not after. I would also put a line fuse between the panel lead and the connection to the battery.

 

[stwendl]

The best solar controller you can get is one of type mppt which best utilizes the solar output and delivers maximum energy to the batteries. Look at it as an impedance match. There are several inexpensive units available. Make sure you pick one that supports your battery type and solar size. Might want to start with Morningstar.

In addition those panels are most likely connected in parallel and should have protective diodes attached to prevent damage when one panel creates more output than the other

 

[Dale777]

I just installed to new 40 w solar panels on the mast and would like to bring the wire down directly to elm where the red master switch is. Can I connect the solar panel wires to the master switch or do I have to go direct to the batteries

As previously noted, you need to have a solar panel controller and an inline fuse. See this link for info:

http://www.solar-electric.com/solar-cha ... sics.html/

Also, you need to ensure that the wiring gauge from the panel to the controller and to the batteries is properly sized to avoid a possible fire hazard. See this link for info:

http://www.freesunpower.com/wire_calc.php

I've included links to RV and solar powered home related sites since I used to have a motorhome, but the solar panel info applies equally to boats.

 

[stwendl]

Marine units are usually a bit more protected from the water (and salt) environments. I would not use all Rv devices on a boat without considering that environment

 

[Pilotnavigator]

Good point, for us fresh water cruisers we forget about the salt water issues. Many of the RV units have aluminium frames that are not anodize for marine environments. But if the boat is used in fresh water only then there is no issue. Just get a real good charge controller.

 

[Dale777]

Marine units are usually a bit more protected from the water (and salt) environments. I would not use all Rv devices on a boat without considering that environment

I see that you are located in Palo Alto, CA. For 38 years I lived in Saratoga, just down the road from Palo Alto, until I retired to Texas and Florida. The Bay Area is certainly a great place to live.

By the way, my post was meant to provide excellent background info about only two things - charge controllers and wire gauge. All the charge controllers, including the Morningstar controllers factory installed on Ranger Tugs, state very clearly in the installation manual: "Do not allow water to enter the controller." This no different than keeping water away from the battery charger/inverters and thrusters. I'm not aware that there are any solar charge controllers that are totally encased to protected from water intrusion.

ppelland stated in his original post that he had already installed the solar panels, which in fact should be properly packaged for the marine environment. So, of course, I was not addressing that area.

Have fun boating in the Bay Area.

 

[stwendl]

Just wanted to pass on my experience ( or better mistakes ) with Rv parts that I installed on my sail boat some time ago. Salty air has a tendency to penetrate devices even in cabins to some degree. That's why marinated electronics are usually sealed and filled with nitrogen inside.

However, I am think our marine inverters and chargers may not be protected like that, and yet they are installed in the stbd cockpit locker. I may be wrong tho