sleepy wrote: I think that everyone knows but I am reminded that any shade on the solar panel drops the efficiency drastically. Even just a leaf.
The cells are all wired in series... when there is shade on any cell the electrons can't flow through it... slowing the whole panel.
I have had my Weingard satelite Television Antenna cast a shadow on our panel and ruin our efforts to recharge the batteries.
I've heard that before, but it doesn't match what I have experienced with my Kyocera's.
I run a few components off my inverter occasionally. One camping site, I knew the panels would begin to be shaded at about 2 pm, so I watched the current output to keep from running down my little house battery.
The controller's current output remained 7.0 A (just what the inverter was drawing) until about 1/4 shading occurred and the current output started dropping to 6.8 A before I shut it all down. The current vrs shade function seems proportional for my system.
"I have never been lost, but I will admit to being confused for several weeks." Daniel Boone
The 9.4amps is from 2 panels...the factory 80 watt and the AM Solar 100 watt.
If you have 180 watts on an MPPT controller, you should be peaking out at nearly 15 amps.
Wouldn't that depend on the rated voltage of the panels?
No.
The point of a MPPT converter is that it can take whatever voltage the panel will produce the most power at, and convert it to the battery voltage.
The MPPT converters are very efficient, and with a 180W panel, you should be seeing at least 160W.
I was under the distinct impression that the MPPT charge controllers worked best with the higher voltage panels and were pretty much a waste of money with the panels in the 14-17 volt output ranges. That's due to not having enough voltage to boost the amperage. Nothing is free in electrical.
Essentially they don't take whatever voltage you have out of the panel, they take the excess voltage you have over the charge set point and use it to boost the amperage. Or did I miss something?
I think you are saying basically the same thing. Ideally the charge controller is going to max voltage according to what a battery can be best charged at, and boost the amperage provided if the amount of watts generated can do so. Better the panels & higher the rated watts, the more amps will be made available at the given voltage.
I personally like the idea of solar, but it won't run my a/c unit.
I don't drink coffee.
The idea of boondocking is appealing to me, but only if the temps are under 70 at night and its quiet. That doesn't happen a lot around where I live and during the same time I can actually get away from work. Maybe when I retire.
Dave & Sue,
DINKS and dedicated to having fun as much as possible.
05 GMC LT crewcab dually
07 Northern Lite 10.2 CD SE, highly optioned version...
A lot comes on a SE.
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