Solar Panels not always working

Maple_Geek

I've been monitoring my stock roof mounted solar panels and I'm getting very poor results so far.
For example, today the camper is in full sun at 1PM and I'm not getting anything.
I pulled the fuse of the solar controller and put it back to reset it but that didn't seem to change anything.
Here are a few screen captures of my settings (defaults).
I am connected to shore power at the moment but I thought that the panel would still show a wattage even when plugged in. 
If you look at the history, it does output at times. I'm puzzled.

VictoriaP

Well, you’re not getting anything right now because your battery is full. 13.67v is a full charge. The state of Float also means the battery is at or very near max charge. The panel voltage at 19.48v means it’s definitely collecting energy, there just isn’t anywhere to put it.

Maple_Geek

@VictoriaP, thank you. Perhaps it's my misunderstanding then. I was under the impression that I would always see something other than 0W when solar was getting sun but that the controller would charge or not charge the battery depending on its status.

VictoriaP

@Maple_Geek Because you have a gel battery (missed that earlier), I’d double check the literature for it to confirm what the max voltage should be. But yes, when it’s full up, you’re likely to see 0w, at least I do with my Victron and portable panels.

Denny16

No, the wattage shows the energy being used, measured in watts.  A 12VDC, 100 watt battery not connected to a load would show 0 watts on a meter, no load, no watts being used.  Add a load to the batter, like a 10-watt light, and the meter will show 10 watts.  The solar panel works the same, and the watt indication on the Victron app is the load being applied to the solar panel measure in watts.
 Cheers 

Maple_Geek

@VictoriaP thanks for confirming that you're also getting 0W when your battery is fully charged. I have a lead-acid battery that was provided by the dealer. These are just the default settings since I didn't change them.

I have been on shore power for a week so the battery is full.

VictoriaP

@Denny16 Hmmm…that’s not how it was explained to me. The SmartSolar is the controller, not a shunt, and I was told the Watts displayed in the app reflect solar watts being provided to the battery…which if the battery is full, would be none. Digging around online to see what I can find about this, the rain here today isn’t conducive to solar testing.

Edit to add: the first two answers on this post on Victron’s site back this up. https://community.victronenergy.com/questions/18415/no-watts-no-amps-but-batteries-are-ok.html

Denny16

You are correct @VictoriaP, the controller does display the load on the solar panel/panels, and a fully charged battery will not provide a load to the solar panel, and will display 0 watts.  A battery needing a charge, depending on the charge rate, will add a load to the solar system, and the amount of charge will show in watts on the display.  

A charging battery is an electrical load, just as turning on the camper’s frig or lights, would also add a load to the electrical system, and as it discharges the battery, the controller will start to charge the battery, and display the watts being used.  

A smart shunt continuously measures the load on the electrical system attached to it.
The solar controller is only connected to the battery, show it only shows the load being applied by the battery.  On the Victron controller, you can add a house load to,it, like the AC/DC fridge, and the app will display the load from a running fridge, and if the battery drops below the minimum set voltage, the controller will turn off power to this accessory load (fridge in this example) connected to it.

Per your referenced comment from Victron, The only time you will see a Watt and Amp value using the App is if the batteries are in need of charging and being charged, or you have a load on the system.
Cheers

Maple_Geek

@Denny16 Thanks. So if I understand correctly, as long as I'm connected to shore power and the battery is full, I should expect to see 0W on the Victron app. How does that explain what the History display shows? I have not disconnected from shore power, yet the panel does seem to work at times.

Denny16

Yes @Maple_Geek, you have it correct.  As for the history, either your AC/DC converter is not providing enough charge during periods of high load and the solar adds some more power to the battery, or the battery is discharging and not getting charged right away from the AC/DC converter.  I have seen this on our TaB400, which is connected to AC whilst sitting here at the house.  I still get some history of the solar system charging the battery.
 Cheers 

N7SHG_Ham

I don't know when you went on shore power or state of battery at that time, but likely the solar was charging as well as shore power until your battery was fully charged and went to float state.

Denny16

That would also explain the occasional charging history, good point @N7SHG_Ham.
 Cheers 

Maple_Geek

@N7SHG_Ham I've been connected to shore power since last Saturday so about 5 days ago

pthomas745

Go out to the trailer with just the solar connected.  Start turning things on: lights, fans, tv, radio.  2 way fridge on battery.  Let it run for a bit...then have a look at your solar wattage on your app. When the Victron senses the voltage drop from your battery doing all that work, then the solar magic will happen.

KathyBob

This is very interesting.  I’ve just noticed the 0 charging value this spring, not in previous years, is new? The Victron app tells me that the solar charger is off because the voltage from the solar panel must exceed the battery voltage by 5V.  I have a stock 2021 400 solar/AGM battery setup and on average with our northern sunlight the panel usually produces 14-17V.  This renders the system pretty much useless unless the battery hits 12V or lower (not a good thing). Would additional panels help?

pthomas745

The question is: what is the state of charge of your battery?  If the battery is fully charged, there is nowhere for the solar energy to go.  The battery doesn't need any more charge.

Show us a picture of your Victron status screen, or tell us what your "Battery Voltage" and "State" say.

And...welcome to the Forums!

KathyBob

Battery voltage is at 12.23 and state just says OFF, then there’s an astirisk that sends you the explanation I noted in my earlier comments 

pthomas745

Is the battery voltage of 12.23 the reading with the battery switch off?  If the battery switch is on, and some small item in the trailer is drawing power, the battery voltage could be showing a "false capacity" reading.  Any voltage meter will display this "false" reading unless the battery is "at rest."

The other thing to look at may be in the "Battery Settings" menu.  There is a toggle to turn the "Charging Off".  So, check that over.

WayneW

@KathyBob Yes, interesting.  I've noticed the same thing.  You can watch the short Victron clip and also watch a more detailed explanation in a link below the short video.  The Victron MPPT controller simply doesn't kick in until the output of the solar panel is at least 5v above the battery voltage, regardless of where the battery voltage is.  It's interesting that once it makes that 5v threshold it doesn't turn off until the output from the panel is less than 1v above the battery voltage!

We're in northern Idaho and we camped several months ago.  I was surprised, even at this latitude and that time of year, the panels were able to reach +5v every day.  However, sometimes it wasn't until mid-day that the rooftop panels were charging the battery - but the trailer wasn't ideally positioned for solar exposure so that definitely affected things.  

Our "solution" is to have a Renogy 100w solar suitcase with a 25' cable that I use to chase the sun, especially in the mornings and evenings.  That redundancy allowed us to keep our batteries fully charged.

We're off on a 20 day trip tomorrow with only 2 places that have a hookup so we'll get a fairly long test of the system.

 

ckjs

KathyBob said:

Battery voltage is at 12.23 and state just says OFF, …

There are two “State” fields, the interesting one in the middle “Battery” section, and the rarely useful in the bottom “Load output” section.

The “Battery” one goes to “off” when the solar input voltage isn’t high enough to start or keep charging. Mine shows a little “i” when there’s no juice from the panel. 

The Load output  is not connected in most T@b’s, unless you specifically wire it up to a small load. (It would be nice if Victron let you enable that part of the display only when it is hooked up.)

Hillbilly

Our 2021 Tab 400 solar system failed completely over the last period with no charging occurring at any time even during very bright days.  According to the Victron application history the panel rarely produces more than 13volts, the solar charger remains in the off state.  I measured the pv voltage at the solar controller and it was consistent with the reading on the Victron app.  I’m assuming that the solar panel is the problem, but I can’t seem to find any info. on what V it should produce in bright sunshine.  It’s the standard setup for a 2021 400.  Any input much appreciated.

pthomas745

On the Victron app, on the battery settings page, check for the "Charger Off" toggle switch is in the "on" position.  What is the battery voltage telling you?

Hillbilly

The charger is on, the battery voltage is barely over 12v.

Hillbilly

The measurements were taken with batteries disconnected 

Denny16

Check the Victron App setup page and make sure it is set correctly, and the battery charged voltage is set to what the voltage reading is for a fully charged battery (usually 13.x VDC).  

Cheers