Is my solar setup faulty?

[Phil_G]

does that mean I would need to disconnect the solar panel again and re-attach it, so it can re-boot itself with a stable power source?

I would, yes. It would give your controller a proper reset and a clean boot up.
Either disconnect one wire from the solar panel, or just throw a heavy coat/blanket over it. Disconnect the battery pos. Leave it a minute.
The appropriate fuse is a convenient place to disconnect.
Cleanly reconnect the battery, ie make it one swift contact. Give it a minute then check your bluetooth stuff. Then let the solar through and look for panel voltage on bluetooth - probably not much today. Your converter should have a resistive floating power supply for testing solar controllers, but I bet he doesnt (around 18-20v at min 4Ω).

 

[monsteruk]

I would, yes. It would give your controller a proper reset and a clean boot up.
Either disconnect one wire from the solar panel, or just throw a heavy coat/blanket over it. Disconnect the battery pos. Leave it a minute.
The appropriate fuse is a convenient place to disconnect.
Cleanly reconnect the battery, ie make it one swift contact. Give it a minute then check your bluetooth stuff. Then let the solar through and look for panel voltage on bluetooth - probably not much today. Your converter should have a resistive floating power supply for testing solar controllers, but I bet he doesnt (around 18-20v at min 4Ω).

Followed the above procedure as instructed. I guess I will just leave it now (maybe with the fridge on) for a day or two, and see if the solar panel starts doing anything.

Thanks again for all your help.

Roy

 

[monsteruk]

I would, yes. It would give your controller a proper reset and a clean boot up.
Either disconnect one wire from the solar panel, or just throw a heavy coat/blanket over it. Disconnect the battery pos. Leave it a minute.
The appropriate fuse is a convenient place to disconnect.
Cleanly reconnect the battery, ie make it one swift contact. Give it a minute then check your bluetooth stuff. Then let the solar through and look for panel voltage on bluetooth - probably not much today. Your converter should have a resistive floating power supply for testing solar controllers, but I bet he doesnt (around 18-20v at min 4Ω).

Hey Phil,

I followed the above procedure with the old battery connectors on (the snap on ones), but to no avail. I have now fitted the bolt on terminal clamps recommended in an earlier response. I will re-try your blanked over the panel, and disconnect re-connect approach and see if it makes any difference.

I shall report back.

Thanks,

Roy

 

[monsteruk]

Hey Phil,

I followed the above procedure with the old battery connectors on (the snap on ones), but to no avail. I have now fitted the bolt on terminal clamps recommended in an earlier response. I will re-try your blanked over the panel, and disconnect re-connect approach and see if it makes any difference.

I shall report back.

Thanks,

Roy

OK, so here are some screen shots taken at various stages of re-setting the solar.

Screen 1 - before I started (van in sun, all connected up, panel open to the sun)


Screen 2 - Panel now covered up, but battery still connected



Screen 3 - Panel still covered up, AND battery positive terminal disconnected



Screen 4 - Panel still covered up, AND battery positive terminal RE-CONNECTED (after leaving a while to ensure reset)



Screen 5 - Panel cover REMOVED (and battery etc. all connected back up), so panel controller should have re-reset? Left it 20 mins in case it takes a while to "sort itself out" after a reset


Weather at 12:20PM when final reading (after reset) was taken. Nice and sunny and 8 degrees, van in sun (see picture below). Whilst it is December, I would expect in sunny conditions it should be providing some charge if it were working? Can we assume from the numbers above that changing the battery terminal connectors and resetting has not fixed the solar charging issues?

 

[Dilbert]

Whilst it is December, I would expect in sunny conditions it should be providing some charge if it were working?

A Victron MPPT charge controller needs the solar panel voltage to be 5V above the battery voltage before it will start charging. Once it starts, it will hold in the on condition until it is around 1V above the battery voltage.

It is surprising how much sun you need this time of year in the UK to get the MPPT started (i.e. solar 5V above the battery). Don't be surprised if most days it will not start. Higher voltage solar panels help in these low light situations.

More info here:

 

[monsteruk]

A Victron MPPT charge controller needs the solar panel voltage to be 5V above the battery voltage before it will start charging. Once it starts, it will hold in the on condition until it is around 1V above the battery voltage.

It is surprising how much sun you need this time of year in the UK to get the MPPT started (i.e. solar 5V above the battery). Don't be surprised if most days it will not start. Higher voltage solar panels help in these low light situations.

More info here:

Thanks for taking the time to respond!

You will see in the earlier posts, it was generating virtually nothing even in the summer days (in the sun in august and over 25 degrees). So this specific test was based on a recommendation from someone earlier about "how to reset the panel", so I was just trying that to see if it improved matters.

A reference I have been using (I am no electrician) regarding panels and what to expect is this one.

Solar Panels and Power for Camping and Caravanning

Learn about common devices used to capture renewable energy for camping, with a focus on solar power. Discover how to capture free, renewable energy here.

www.campingandcaravanningclub.co.uk

There is a table in that link which is as follows:


Which indicates what you can expect on an average day in the UK based on your panels rating (mine is 150W). I think the most I have ever seen from mine (even in the summer) is around 50wh in 24 hours. So even in the summer, I get less than half what the CC club expect a panel of that rating should generate in the winter!

I will see what if anything changes in the next few days. But I would be astounded having spent an hour outside at lunchtime if there was not enough sun to even inch toward the 120Wh a "winter day" shown in the CC club article.

Cheers,

Roy

 

[oldiebut goodie]

I don't use all that fancy monitoring but the fact that your solar panel isn't showing 0v when you connected the battery means that you haven't reset the controller. Why cover it up and not disconnect it at the controller?
My little 20w top up panel sitting on the dash of my T-Cross was charging at 14.7v at around noon today when I checked it ( battery was at 12.5v).
I suspect that if you disconnect the panel entirely - only one wire, then connect the battery first your controller will burst into life correctly.

 

[monsteruk]

I don't use all that fancy monitoring but the fact that your solar panel isn't showing 0v when you connected the battery means that you haven't reset the controller. Why cover it up and not disconnect it at the controller?
My little 20w top up panel sitting on the dash of my T-Cross was charging at 14.7v at around noon today when I checked it ( battery was at 12.5v).
I suspect that if you disconnect the panel entirely - only one wire, then connect the battery first your controller will burst into life correctly.

Thanks for that @oldiebut goodie. I was trying to follow some instructions someone else posted further up.

I am hopeless with electrics. So, where you say disconnect a wire from the solar completely. Can this be done from on the top of the panel itself? I.e. at this location, where the cables leave the panel?



Or do I need to take the cover off of the MPPT controller and disconnect a a wire from there?

Sorry for the stupid questions!

Roy

 

[oldiebut goodie]

I would disconnect it at the controller as that is easiest and saves opening any watertight join, that way you will see 0v on your screen ( unless it has been wired up wrong all along). You only need to disconnect one wire for the panel to stop feeding the controller.

Just looked at your controller - either one of the right hand pair. No need to remove cover just loosen the screw holding the wire in.

 

[Dilbert]

Which indicates what you can expect on an average day in the UK based on your panels rating

Those figures look pretty ambitious to me. I assume they are looking at a panel in an optimum elevation to collect maximum energy. Our vans have the panel horizontal when parked up, often with water on them and the sun is much lower in the sky in winter.

I have just checked my Victron history for the last couple of weeks on our 160W panel. The maximum I have seen on a particular day is 30Wh with the panel giving a max power of 8W! Today the panel has given a maximum voltage of 22.84V so enough to start the MPPT charging but it has only yielded 2W.

This same panel will easily put 10A from the MPPT into the battery when in Spain!

 

[monsteruk]

I would disconnect it at the controller as that is easiest and saves opening any watertight join, that way you will see 0v on your screen ( unless it has been wired up wrong all along). You only need to disconnect one wire for the panel to stop feeding the controller.

Just looked at your controller - either one of the right hand pair. No need to remove cover just loosen the screw holding the wire in.

Brill I will take a look at first light! Last pic I took the controller is here:



Will have a proper look tomorrow, but from what I remember, I couldnt see any screws (so assumed needed to remove cover). I will have a peek in the morning though and checl

Thanks,

Roy

 

[oldiebut goodie]

Screws in these holes under the letters.

 

[monsteruk]

Screws in these holes under the letters.

View attachment 95361

Thanks @oldiebut goodie ,

that makes sense and I know what I am looking for now. So, just to be 100% clear as I am gonna do this at first light. The procedure is...

1. Disconnect one panel cable from MPPT
2. Disconnect positive battery terminal
3. Wait for a few mins for it to all "shut down".
4. Reconnect panel cable to MPPT
5. Reconnect battery positive terminal.

Cross everything and hope for the best? Should I be checking voltage via bluetooth at any key points?

Is that about right?

Cheers,

Roy

 

[oldiebut goodie]

No........

4. Reconnect battery positive terminal. Wait a few minutes for the MPPT to adjust to the battery voltage.
5. Reconnect panel cable to MPPT

You can watch the voltage and check that it zeroes with the panel disconnected and then shows again at the end of reconnecting.

 

[oldiebut goodie]

Looking back at your panel voltage - it seems a little low to me as my little one mentioned above was showing 14.7v today and that was sat on the dash and the screen was misted over as well due to all the moisture in the air.
I wonder what others think about it.

 

[Dilbert]

Looking back at your panel voltage - it seems a little low to me

Could be, 13-14V is a typical voltage when only half of the array is working when in bright sunlight.

Need to get the controller reset as you instructed to make sure the voltage readings are correct.

 

[Phil_G]

Why cover it up and not disconnect it at the controller?

I was trying to follow some instructions someone else posted further up.

Actually what I said was

...
Either disconnect one wire from the solar panel, OR just throw a heavy coat/blanket over it.

Why? because Sniggs has said that he's uncomfortable around electrics and completely shading a panel reduces its output to zero quickly, easily and with out him having to touch any wires at all. I'm just trying to help him!

 

[oldiebut goodie]

With a cover over the panel it was apparently still showing voltage not zero which is why I said that.

 

[monsteruk]

No........

4. Reconnect battery positive terminal. Wait a few minutes for the MPPT to adjust to the battery voltage.
5. Reconnect panel cable to MPPT

You can watch the voltage and check that it zeroes with the panel disconnected and then shows again at the end of reconnecting.

OK @oldiebut goodie,

I have now followed the instructions and repeated the procedure, this time actually disconnecting the panel cables. Here are the scores on the doors. Weather isnt great today (dull and drizzle), but from what I can see it hasnt made any difference (to my untrained eye).

Step 1 - disconnected solar cables.



step 2 - disconnected battery (as expected, cannot attach to MPPT from bluetooth at all, and all lights off on MPPT)



Step 3, after a good long wait, re attached battery terminal (so could reconnect on bluetooth).



Step 4, after a ANOTHER good wait, re attached solar cables (probably waited around an hour)




The panel voltage at the end of the process (shown above) of 12.79 is actually slightly less than it was yesterday before the reset (but it was brighter yesterday).

So, after going through this process I think we can rule out the following as the cause of the "battery not charging via solar issue".
1. The poor connectors on the battery terminal (these are replaced with the bolt on type now and are rock solid).
2. The solar / MPPT needed resetting. Followed the above process to do that, and it seems to have made no difference.

So, with this all in mind. Is there anything else I can do as a simple test to try and isolate the issue further? E.g. I know how to disconnect the solar cables to the MPPT now, is there any point checking the voltage at the end of the solar cables with a multi-meter? Would that tell us anything? Or is there something else I could try?

Thanks again...

 

[Dilbert]

The panel voltage at the end of the process (shown above) of 12.79

My 160W panel is showing a range of around 15V to 19V today but it is raining and overcast. The actual voltage you will get in any light conditions depends on the specification of the panel. The array configuration, number of cells, etc. will affect the open circuit voltage* specification (* the maximum voltage the panel will produce with no load at all).

MPPT charge controllers work best in low light conditions with higher voltage panels (assuming the panels are within the maximum voltage rating of the controller - which is 75V in your case). Do you know the make and model of your solar panel? Do you have the specification data for it?