Selecting a solar panel, brands, and requirements for RVs?

dwh

Tail-End Charlie
Is this sittuation bad?????????? or ok?

Non-issue.

They are only tied when the voltage is being pushed up above their normal resting voltage. It won't hurt the batteries to get some extra absorb time, and it would happen anyway if you were just driving.

The solar doesn't change that, it just increases the available amps a bit while driving. Whether or not the batteries can absorb more amps than the alternator can supply is a different question, and the solar might (probably will) end up doing nothing much with the engine running.

With a small solar system, it's when the engine is idling or off that the solar matters.
 

dwh

Tail-End Charlie
That's sort of a silly thing to say, and I would have expected better...

Now now, don't get defensive. I wasn't attacking the Grape nor recommending the Kyocera.

The OP asked what Earthroamer uses. I said I think they used to use blah blah blah.

Since there were already links posted to the thread for both, I decided to point out something else he should consider...weight. He did mention putting it on top of a tent or some such.

In which case, he might prefer the lighter weight of the Grape over the heavier snow load rating of the Kyocera.

Doesn't matter to me what he does. I don't care. But it might matter to him.


The extra weight of the Kyocera is glass and aluminum, but is also physically significantly bigger. Makes sense, it's a less efficient panel.

Makes sense? I'm not so sure it does.

Here's food for thought: If the Grape is 18% efficient, and the Kyocera 16%, that's a 2% difference.

Yet the Grape is 25% smaller (and lighter) for the same rated 180 watts.

How?
 

calicamper

Expedition Leader
Fewer cells and better quality. The 310watt LG panel was the same size as the 285s I ended with. Has to do with cell density and quality for higher output.

My set up did 45kwh today;-) Microinverters 29 panels on the house.

My little camping rig is 2 10watt Renogy panels and a 18ah battery in a 50cal ammo box. Both ends of the spectrum. Fun stuff though.
 

AndrewP

Explorer
Makes sense? I'm not so sure it does.

Here's food for thought: If the Grape is 18% efficient, and the Kyocera 16%, that's a 2% difference.

Yet the Grape is 25% smaller (and lighter) for the same rated 180 watts.

How?


I don't want to belabor this, but you know better. It's not 2%. It's 2/16 which is 12.5%. You are trying to confuse people with statistics which is not cool. I can play that game too and won't.

But anyway, most panels with an aluminum frame will be pretty robust. There are super high quality/efficiency panels out there, but almost unneeded for an off road truck.

Since our market is very small, no one will ever make the ideal solar panel for us. Instead, we will always be using and adapting a panel that someone developed for a different purpose. To me, the ideal panel would be 200 watts, 45 volts with the highest possible efficiency to keep it as small/light as possible. A good MPPT like a Victron BlueSolar, and good to go.
 
Makes sense? I'm not so sure it does.

Here's food for thought: If the Grape is 18% efficient, and the Kyocera 16%, that's a 2% difference.

Yet the Grape is 25% smaller (and lighter) for the same rated 180 watts.

How?

2% relative efficiency is not a 2% difference from 16-18. More like 12.5% shift in efficiency. ;)
When the panel is smaller, the case rails do not need to be as thick, in addition to being shorter. That can save a lot of weight.
They are always using every trick they can to maximize wattage per footprint. Getting the interconnect wires off the front of the cell is a big deal. I am surprised its not more common. We were talking about that in 2009.
(Although i know very little about setting up a solar array, I worked for applied materials crystalline silicon solar division back in 2009. We built wafer processing equipment, and i never dealt with the end user aspects of this stuff).
 

dwh

Tail-End Charlie
I don't want to belabor this, but you know better. It's not 2%. It's 2/16 which is 12.5%. You are trying to confuse people with statistics which is not cool. I can play that game too and won't.

Sweet of you to volunteer to figure out what motivates me. Interesting that your analysis assigned me such nefarious motives.

But your analysis is wrong.


And you're also wrong on another point - pop quizzes are cool.



(And is it 2/16 or 2/18?)
 

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