Solar Panels

edcooke wrote:
I have a factory installed 100 watt solar panel on my Artic Fox fifth wheel and would like to add another 100 watt panel. The manufacture tell me the solar charger will handle another 100 watt panel. The wiring to the batteries is adequate for two panels. The output voltage on the current panel is about 16 volts.

Do I just buy another 100 watt panel with the same output voltage and hook it up in parallel to the existing panel?

Any advise on how to do this would be helpful!

Thanks

I worked on someone's rig who had been told the same thing, and in fact the dealer installed the panel for him. He had 225 watts on the roof and a 10 amp controller. Couldn't figure out why it wouldn't charge.

I don't trust what anyone tells me unless they show me at the same time and it makes sense to me. If what they say is true, sure, just add another 12v nominal panel and wire it to the other one in parallel (positive to positive, negative to negative). But I'd verify what they said first. Get the controller make and model, then the wire size and estimate the wire length. Post it here, you'll get plenty of suggestions.

Yes, buy a second 100 watt panel. Or a larger or smaller one if you like. As long as the maximum power voltage (Vmp) is close (within a volt I would say) you should be fine. Hook them in parallel and you're done.

RJsfishin wrote:
You are talking 10-12 amps on a good day. How undersized could the wire be ???
And even if it was 14 gage instead of 10 gage, what we loose, 1 amp ??

Parallel another panel and be done w/ it. The voltage or amperage doesn't have to be exactly the same either.

It's all about power loss in the resistance of the wire. 10 gauge wire has a resistance of about 1 Ohm per 1,000 feet. 14 gauge is about 2.5 Ohms per 1,000. Heat loss is the square of the current times the resistance. It really depends on how long the cable run is.

You are talking 10-12 amps on a good day. How undersized could the wire be ???
And even if it was 14 gage instead of 10 gage, what we loose, 1 amp ??

Parallel another panel and be done w/ it. The voltage or amperage doesn't have to be exactly the same either.

That would be the easiest and lowest cost option.
However, I would question if the manufacture really put in adequately sized wire. So if you want the most power possible (watts per $), then you may want to take a second look at the wire size used (between panel and controller AND between controller and battery). Post those sizes and lengths to the forum and you will get more help than you know what to do with.

Steve

Yes.

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