Wiring a Solar Panel to the Battery Banks

[Mickey G.]

I just purchased a 20 amp solar panel with a charge controller to keep my two battery banks charged while on a mooring for the summer. I also have a new smart battery charger to charge the four batteries in the two banks. 2 house batteries and one windlass battery on switch 2 of the battery switch and one deep cell battery on switch 1 for starting the engine. I believe all four batteries at group 27, but I could be wrong there. I know the two batteries for the house and one for the starter are group 27 but the windlass battery could be smaller. It was wired by a marine electrician who know his "stuff". Everything there had worked for 10 years so I expect it was done properly.

The old charge only was set up for two banks where the new charger can do three but I am only using two so I don't have to do any additional wiring for now.

Now that I am no longer going to be in a slip....alas the solar panel.

Now the question.... how do I wire the panel properly to keep all four batteries charged?

Should I really have two controllers, one for each bank or should I put all four batteries in parallel? Should I connect the wire after the controller to the ALL switch or is there another way?

 

[Dave D]

unfortunately, My bank is only 2 batteries, but I was advised to leave them in parallel and attach the charger (mine is a 15W) to the battery selector swith to keep the wire runs about equal and to allow equalization.

Here is a link to the thread at a 12V Head forum. AS with most forums, some great helpful advice, plus the occasional weenie thrown in.

http://www.electro-tech-online.com/...onnecting-solar-charger-2-12v.html#post741642

I can't be of much help but maybe they will tolerate another question or two from us pesky sailors.

 

[natotm]

20 amp or 20 watt? 20 amps is a very large panel...

 

[Ron McCoy]

I agree, I think you mean 20 watts - not amps. When I installed my solar panel, a 130 watt Kyocera, I terminated the wiring from the solar panel to a 15 amp breaker switch, then to the charge controller, then to the common post associated with your "house" battery switch. On Hunters, these post are not the battery switch themselves, but a large bolt that ties all the battery leads together and the "ON" position of the house battery switch. In this confiquration, your solar panel is feeding all batteries, regardless of how many you have. If the batteries feed the battery switch when ON, then so will the solar panel. The charge controller willl regulated how much the batteries willl accept based on their state of charge and of course whether the solar panel is producing electricity. Pretty staight forward if you study the wiring connections in your boat. Good luck.