Recently I bought a 35 watt 12v solar panel, I have a small pond 5 watt panel that supposedly is 12v as well. I wanted to combine and use both of these panels for an off grid application. I want to install these in parallel to keep the voltages the same, I know that I will lose some output wattage due to connecting/mixing panels of different amps. My confusion comes in on how to connect them together, what is the best possible way.
Should I connect them together in parallel first then run one positive and negate wire to the controller? Or should I run both panels, 2x positive and 2x negative wires to the controllers + and - terminals? Right now I’m looking at a PWM controller but I’m not sure how well this will handle what I’m trying to accomplish. Should I use a MPPT controller instead? I rad that its better to keep batteries that are not of the same specs separated, for example using two controllers since most controller only have one + and – terminal. I could plug the 5 watt into one controller and the 35 watt into the other then run the wires from both controllers to the 12v battery. This seems a little excessive for what am doing but im looking for a safe way to do this and get the most watt output possible.
Also have have these panels mounted on a fence post, the post is obviously in the ground, should I be grounding any of the other components ? Im assuming since the post is in the ground that its grounded and so I are the panels attached to it via a metal bracket?
One last thing, I know that panels have many voltage ratings and one is VOC, when I tested the 35 watt panel the VOC was 21 volts as stated in the panel, however the 5 watt was only about 10v, there is no specs sheet on this panel. I know they produce difference amps but is this VOC reading on the 5 watt normal?
My last question is where should the load plug into, I know the charge controllers have a load terminal, but if I want to plug in more then one load I read that I should be connecting directly to the battery, is this correct? I know I might need a bus terminal if this is the case.
I would appreciate any responses and thoughts to this, this is my 1st time doing something like this and I want to get it jut right. Thanks, Paul