Panel has voltage and current, but wont charge

[solaar]

I have a 100W flexible panel hooked up to a victron charge controler which wont charge. Another 120W panel I have works just fine in the same setup. Multimeter shows 18+ Volts and around 5A of short circuit current at the panel and also after the extension cable attaching it to the charge controler. I have tried a different charge controller and it wont work there either.

It is doing my head in, how can it not be working when there is plenty of voltage and current?

[Mike90250]

If the controller thinks the battery is fully charged, it won't do any charging. And be sure you power up the controller in the proper sequence, boot from the battery and then apply solar PV. Shutdown the opposite Remove PV solar power, and then disconnect from battery, The controller "brains" draws power from the battery terminals, not the Solar PV

[solaar]

I always use the propper connection sequence and the controller will charge on one panel but not the other, so I don't think it is misinterpreting the battery charge.

[littleharbor]

A faulty solar panel can give open circuit voltage OR short circuit amperage by themselves. Open circuit voltage or short circuit amperage by themselves are not power as it takes both to give you usable power. You need to test this panel under load. Take a 12 volt automotive light bulb and put it inline when you do your short circuit amperage test. In full sun, if your panel works you should get a brightly lit bulb

[SunEagle]

I am thinking there is a wiring issue on the output of that flexible panel or it does not produce the proper voltage to get the victron CC to start working.

Have you tested that panel on something that works or have you performed the test that littleharbor suggests?

[Sunking]

A dead battery looks just fine to the controller. Disconnect the battery, measure the voltage, then put a load on the battery and measure the voltage again. If the voltage crashed, you have a boat anchor.

[PNjunction]

I'm with SunEagle - use your multimeter to check the *polarity* as well.

Many products in the 12v arena wire up their cabling and connectors differently from one another, so you have to check with a multimeter for polarity if you swap different manufacturers cables.

Ex: Harbor Freight / Sunforce / Coleman cables can differ from other products producing a reverse-polarity problem, especially if the wiring going to the typical push-on SAE connectors are used and not checked. In some cases, the wiring directly from the panel itself can be wired wrong, but the wrong polarity wiring fixes it!

This leads to a lot of hair-pulling and cable swapping (or worse) if you don't verify the polarity first.

[ILFE]

I have a 100W flexible panel hooked up to a victron charge controler which wont charge. Another 120W panel I have works just fine in the same setup.

Sounds like, to me, you just have a bad panel. Could be as simple as that.

[solaar]

Thanks everyone. I am on a road trip at the moment, so resources are a bit limited and it is monsoon season so sun is scarce. I haven't tried testing with a load yet - good to know - but today I measured again and the flexi panel was only putting out 9V while the rigid one was putting out 20V in the same light. It seems like the thing is cactus and maybe my multimeter is crap too. The panel has worked fine for months, so polarity was not an issue. I tried it on an another old charge controller I took with me - just some quick dodgied up test wiring but nothing there either - in good sunlight too. My battery is fine - only months old.

The flexi was glued to my trailer where I was going to do the bulk of my charging, so I have wound up having to remove it and mount the rigid panel in place. A job I really did not want to be doing on a road trip! I will test it properly when I get home I think, but it may be a warranty job.

[Switchback]

I'm a bit late to the conversation, but I had a similar problem on one of my panels last year. Tested fine without load. Once the load was put on it I got nothing. The problem with mine was a bad solder connection in the panel. There was a good enough connection to test voc/isc but the connection wouldn't carry a load.

12v bulb is a good test. You could also wire the panel direct to the battery and then use your multimeter to see how many amps your charging, if any. Direct wiring to a battery would eliminate any potential controller/wiring/connection issues