Solar, Volts No Amps

[StuM]

Originally Posted by cstan22

Not sure how to tell. It's a Votronic 420 Duo Digital. User manual says Max volts are 50 V. Says for a 12 V system, the VoC should be between 20 and 23 V. Is that the number you're asking about?

The three 100 W and the 160 W all say ~21 V on the multimeter. The poly panel only reads ~16 V. There used to be two of the same of the 100 W poly panels, but one stopped showing any voltage, so I assumed it was dead and purchased the 160 W mono as a replacement. All of these came from the previous owner.

Yet you expect the Voltronic to work with the poly panel by itself?

[john61ct]

Originally Posted by Stu Jackson

$200 Canadian. Sure, inexpensive enough.

Pretty sure the Votronics aren't cheap units, OP hasn't stated they're poor, and obviously suggestions as to what is best are offered as, yes, suggestions.

And yes when good quality MPPT with even a subset of those features has traditionally been USD $400+, I do maintain that the value and flexibility of the Victron series is excellent, especially for managing a bunch of heterogenous panels

[hellosailor]

cstan-
I think you need to back up a step and load test some panels. Simplify, divide and conquer. Take one of the "known good" panels, run the output leads directly to a battery, any battery, preferably one that is not fully charged. Insert you ammeter in that, between the panel and the battery, and see what voltage and amperage you are getting.
Now repeat the test with your "dead" panel. If the dead panel is still not providing any amperage to that battery, then either the panel is dead, or the wiring from the panel has a problem. To eliminate that question, open the junction box on the back of the panel, find the point where the leads come out of the panel and the wiring starts. Put your multimeter on the 200 or 2000 ohm range, and measure the resistance of each power lead--while the power leads are disconnected from the battery, of course. End to end, each power lead should show a resistance of nearly zero ohms. Maybe one or two. If the power leads show higher resistance or infinite resistance--that's the culprit.

Yes, if you had three 20v panels in series with a controller that has a maximum input of 50V, you could blow it out. But first, try to find out what part of the panel or the wiring is not working, then worry about the controller after that. (Assuming there's time before you leave the boat.)

Divide and conquer. One component, one piece, at a time.

[KP44]

Originally Posted by smac999

Why do you have so many different panels connected To to the same controller? They should be indentical.

I cannot diagnose your problem.
But I use a separate controller for each group of solar panels. Or a separate controller for each panel, if they are tilted different directions or one might be in the shade; or any other difference. That way one "excellent" panel is not dogged down by a shaded or shorted panel.
Several small controllers instead of one master controller. But I an still learning and experimenting. There are wiser people in this forum.