Connecting a 100 watt solar panel to Zamp port

Moon glow is not sufficient to produce any output for a solar panel.  It might produce just enough to register on a multi-meter, and probably a very sensitive one at that, but not enough for any usable purpose.

Heck, the lights in your house aren't strong enough to power a normal solar panel, so there's no way that the moon will.  Solar panels don't work when it's cloudy, rainy, or at night.

 

In large arrays, like for a cabin or home, this is how it is done.. with one caveat.. They are not running a "12v" system. You use a higher voltage sytem from the get go. Most home/cabin, etc installations run at 48v. Some at 24. Depends on the total load allowed for. This could be done with an RV.. but not real easy in the confines of a Pod. Quality higher input/output inverters also get expensive quick.

 

Next time I am over in Menonite country, I will get a picture of one of their systems running my favorite country store/bakery... It's a 48v system built on Group 8D batteries in series. Just the battery bank is big as a Pinto..

John, with a higher voltage solar array you are quite correct that the current would be lower at the same power rating. This does have advantages in having lower voltage drop (and lower power loss) with a given power output and wire size. Consider two examples:

Now to get that advantage, you don't need to wire two panels in series. They make higher voltage solar panels that are used in high voltage DC systems or in grid tied systems. For instance I have a 36 volt, 185 watt panel made for a grid-tied solar system. It puts out around 5.1 amps at 36.4 volts. With that panel I can have less than 3% voltage drop with 10 gauge wire running 75 feet.

Here's a good link to a handy voltage drop calculator.

The good news is that you do NOT have to run your camp trailer at the higher voltage. A maximum power point tracking controller (MPPT) runs at the higher voltage for maximum efficiency, lower power/voltage loss in your wiring. But it then conveniently does a voltage conversion to provide for charging a 12-volt battery. In clear text you can use a 36 volt panel to charge a 12-volt battery with a MPPT controller. A 36 volt panel can be found with a diligent search on the internet. They are actually quite common, many thousands being made for the grid-tied market. Here's an example of such a panel at a reasonable price:

Back to the example of my 185 watt panel. Between the solar panel and controller, the voltage is around 36 volts at 5 amps. From the controller to the battery the voltage is between 12 and 14.7 volts depending on the battery charging needs. Current into the battery is up to 15 amps. Since the MPPT controller is mounted on the battery box, the panel can be up to 75 feet away (with 10 gauge wire). The higher current, low voltage line running from controller to the battery is around a foot long, with minimum voltage/power loss.

Here's a photo of the 185 watt panel, MPPT controller and battery. I'm sorry that the photo is so enormous. I can't seem to get it small enough to view the whole thing without scrolling left and right.

The charge controller is a Morningstar SSMPPT-15L. It runs around $225. But considering the advantages of a high voltage panel, the extra cost is well worth it.

 I hope that my thoughts here will be of use, John. If you have any questions, let me know. I would be pleased to be of help.