Proper way to Wire Solar in Parallel?

This diagram shows connecting two 6VDC BATTERIES in SERIES and
two 12VDC BATTERIES in PARALLEL to get 12VDC.

Not sure I was able to understand what the QUOTED INFO you had copied was meaning...



My SOLAR WIRING CONCEPT will probably initially look something like this for my PLAY MODE to get better acquainted with solar panels and what to expect.


I eventually will want to use a SMART RELAY setup like this BLUE SEA SI-ACR to mix the solar panel sources into my battery bank setup in a more automated way of keeping may batteries charged up..

All PHOTOs from google images

Roy Ken

I have the same setup like you described with 2-12V batteries in parallel and they are setup like RoyB's diagram. Negative off one battery, positive off the other battery going into the trailer. I do the same with my solar panels and span across both batteries

The 12 volt batteries are wired properly as shown by Roy. The reason is that you want to balance both the charge and discharge cycles across the storage capabilities of the batteries. In other words, you want to draw equally from all plates as well as then charge them equally. Physics defines the characteristics of how electricity flows...and the method shown will best balance the charge and discharge cycles across the battery bank. If you are really trying to balance the bank then you also need to pay attention to the size of the wiring and the length of each wire, but that is beyond the scope of this answer.

Solar panels in parallel are not storing power or being charged. Thus they do not need to be wired in the same fashion. Simply attaching all positives together (typically in a distribution box) and all negatives together is correct. It is best to home-run them to the distribution box, and not to daisy chain them to each other. This mitigates wiring failures better, and more importantly, it keeps within the ratings of the junction boxes on the panels.

Jack Mayer wrote:
The 12 volt batteries are wired properly as shown by Roy. The reason is that you want to balance both the charge and discharge cycles across the storage capabilities of the batteries. In other words, you want to draw equally from all plates as well as then charge them equally. Physics defines the characteristics of how electricity flows...and the method shown will best balance the charge and discharge cycles across the battery bank. If you are really trying to balance the bank then you also need to pay attention to the size of the wiring and the length of each wire, but that is beyond the scope of this answer.

Solar panels in parallel are not storing power or being charged. Thus they do not need to be wired in the same fashion. Simply attaching all positives together (typically in a distribution box) and all negatives together is correct. It is best to home-run them to the distribution box, and not to daisy chain them to each other. This mitigates wiring failures better, and more importantly, it keeps within the ratings of the junction boxes on the panels.

Thanks Jack. This helped a lot :)

Yes you can, connect one panels wires to the second panels terminals and run one set of wires to the controller
Always run only one pair of wires to the controller
In cases of multiple panels, most installations
consist of wires run from each panel to a "gang" box
Connect all wires together in gang box and run large pair to controller

CnadianFF wrote:
I found this in another thread regarding batteries.

"Looks like your batteries are not hooked up correctly. If you are using 2 x 12v in parallel then you should feed the trailer with the negative from one battery and the positive from the other battery. Your hookup shows you are feeding from just one battery with the other battery cable attached. I do not think this is the correct way. Check the "12volt side of life" for pictures."


Would the same thing apply to solar panels? I have two panels on a 12 volt setup. One panel is wired in to the other panels terminal box then the wires run from the terminal box to the battery in a daisy chain parallel setup. Is that ok? Thanks