Victron Threshold or Faulty Solar Panel?

[Deviant Tubs]

You can see form the voltage output from the Panel that it's barely changed all day!

'Apparently' it's generated the same Voltage at 9am and at peak sun at 1300!

 

[t0mb0]

After speaking with Lifos on the phone about trying to get the Bluetooth BMS up and running they confirmed that a discharge should reset it. They also confirmed that 6v was equivalent to a full discharge. They did not seem to think it needed 24 hours to rest(?)

So I switched on the Solar Charger and started charging the battery up again.

The Battery very slowly started taking charge at a rate of 12V and 14 Watts which seems ridiculously low (it's full sunshine and glorious today) and then abruptly stopped at 9v!!!

The voltage from the panel is currently at 14v (again, it's full sunshine outside and glorious) and the Wattage is reading as 0.

I plugged in the EHU and the Battery quickly took charge, zooming upto 13.2V suggesting that the Cell at least is decent.

The BMS App sadly however has not come back online so I can't check the SOC (might pursue a Warranty claim from Lifos because that's major rubbish but that's another story!)

Looks like it maybe the Solar panel afterall. I've ordered a suitcase solar panel to test if the Battery will accept charge from a different piece of hardware.

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I wouldn't read too much into the wattage itself whilst the battery is still very depleted - it's possible that it has a mode to try and gently bring the battery back from a very depleted state - it would be a concern if the wattage didn't increase (whilst sunny obviously) as the battery gets out of a very depleted state though. The panel voltage does seem to be cause for concern though, from your previous screenshots it seems as though the expected voltage is closer to 20v so that reading 12-14v does seem to indicate a problem. Can you verify that voltage with a multimeter at the terminals just to discount the possibility of a dodgy measurement from the MPPT? Preferably also measure the same voltage as close as possible to the panel itself too to discount a connection problem. If you have confirmed significantly under-spec panel voltage in decent sun then unfortunately it is likely to be a dodgy panel. Keep an eye on it when the sun is less strong too, quite often the contacts in the panel break as they heat up which causes the voltage to crash when it's actually most sunny.

 

[t0mb0]

You can see form the voltage output from the Panel that it's barely changed all day!

'Apparently' it's generated the same Voltage at 9am and at peak sun at 1300!

View attachment 257228

Can we see this same plot over the course of a month or so? That should show the point of solar panel failure if it occurred over that period.

 

[aferris2]

You can see form the voltage output from the Panel that it's barely changed all day!

'Apparently' it's generated the same Voltage at 9am and at peak sun at 1300!

View attachment 257228

That doesn't look as though the panel is working properly. Can you get a plot covering the whole day from before light until it's dark (so about 4am to 10pm). That should show how the panel responds to light / no light.
If the panel is failing due to heat, you should see it beginning to work as it gets light up to the point that heat from the sun gets into it. Similarly, it might spring back into life as it all cools down at the end of the day.

I'm still puzzled by the extra wire (thinner red) connected to the solar +ve. Where does this go? You should really only have two wires to the solar panel - one -ve and one +ve. If that thinner red wire connects to anything on the starter or leisure batteries it's going to do something strange and that could be what we are seeing in your plots.

Not mentioned so far (I think) - do you have an isolator switch or any joins in the cables between the MPPT and the solar panel? If there are any, check these for continuity.

 

[The Bear78]

Sorry to jump in on this thread when I have nothing useful to add...
I am at the planning phase for a Solar set up so all threads like this are useful to get a feel for how different system operate and what to expect.
One thing I am wondering is the meaning of the text at the bottom of this screen talking about the charger. Does this link to a help page or something similar or have you ( @Deviant Tubs ) added that text to the image please?

 

[TallPaul_S]

Yeah, it basically goes to a page where it tells you the few reasons why the charger is off - ie the battery is full, solar panel isn't generating enough voltage/amps, etc etc.

For example I've just turned mine off in the app, when I then click on that message is tells my why it's off.

 

[The Bear78]

Thank you.

 

[Deviant Tubs]

That doesn't look as though the panel is working properly. Can you get a plot covering the whole day from before light until it's dark (so about 4am to 10pm). That should show how the panel responds to light / no light.
If the panel is failing due to heat, you should see it beginning to work as it gets light up to the point that heat from the sun gets into it. Similarly, it might spring back into life as it all cools down at the end of the day.

I'm still puzzled by the extra wire (thinner red) connected to the solar +ve. Where does this go? You should really only have two wires to the solar panel - one -ve and one +ve. If that thinner red wire connects to anything on the starter or leisure batteries it's going to do something strange and that could be what we are seeing in your plots.

Not mentioned so far (I think) - do you have an isolator switch or any joins in the cables between the MPPT and the solar panel? If there are any, check these for continuity.

If memory serves correctly, that extra cabling is a feed to an Anderson connector that terminates under the bonnet. This works as an Auxiliary input for the Solar. Meaning I can have a suitcase style Solar panel working in conjunction to/instead of the roof panel if needed

 

[Deviant Tubs]

Feed under the bonnet which I suspect is gointhe extra cable running to the Solar Controller

 

[Deviant Tubs]

That doesn't look as though the panel is working properly. Can you get a plot covering the whole day from before light until it's dark (so about 4am to 10pm). That should show how the panel responds to light / no light.
If the panel is failing due to heat, you should see it beginning to work as it gets light up to the point that heat from the sun gets into it. Similarly, it might spring back into life as it all cools down at the end of the day.

I'm still puzzled by the extra wire (thinner red) connected to the solar +ve. Where does this go? You should really only have two wires to the solar panel - one -ve and one +ve. If that thinner red wire connects to anything on the starter or leisure batteries it's going to do something strange and that could be what we are seeing in your plots.

Not mentioned so far (I think) - do you have an isolator switch or any joins in the cables between the MPPT and the solar panel? If there are any, check these for continuity.

I think you might be onto something here..
Looking at this morning I can see that there was a surge in Power Output just as the sun was rising (approx 6am) it climbs to 30V and then nose drives at 08:37 at which point it barely scrapes 15v

 

[t0mb0]

I think you might be onto something here..
Looking at this morning I can see that there was a surge in Power Output just as the sun was rising (approx 6am) it climbs to 30V and then nose drives at 08:37 at which point it barely scrapes 15v

View attachment 257242

Yeah, that is a smoking gun for a knackered panel sadly. There's a tiny chance it's a temperature-sensitive connection issue in the cabling between the panel and the MPPT, but far more likely it's a connection within the panel itself.

 

[Deviant Tubs]

Looking back at the last 7 days it would appear that the panel climbs to a reasonable voltage each and every morning and then just falls off as the temperature climbs

 

[TallPaul_S]

Have you ever used that for a 2nd panel?

Just plugging the 2nd panel wires directly into the MPPT isn't a good idea.

You're effectively running them in parrallel, which means the system voltage will be at the lowest panel voltage.

Using Mismatched Solar Panel Sizes in the Same Array

This blog post will teach you how using mixed and mismatched sizes of solar panels in the same array will affect the output of the entire array.

explorist.life

And of course you don't want a portable panel with it's own controller going into an MPPT...

I think you might be onto something here..
Looking at this morning I can see that there was a surge in Power Output just as the sun was rising (approx 6am) it climbs to 30V and then nose drives at 08:37 at which point it barely scrapes 15v

View attachment 257242

That's a failing panel, alright.

Mine does the same with the rise in voltage, but stays high.

 

[Deviant Tubs]

Yeah, that is a smoking gun for a knackered panel sadly. There's a tiny chance it's a temperature-sensitive connection issue in the cabling between the panel and the MPPT, but far more likely it's a connection within the panel itself.

Really appreciate your advice on troubleshooting this issue - so many variables it's tricky to know where to start.

 

[Deviant Tubs]

OK I'm gonna go chuck a bucket of Ice water over the roof and see if it comes to life for a bit!

 

[Deviant Tubs]

A few days later...

So I spoke to the suppliers of the solar panel, they agreed that the issue was almost certainly due to a hardware fault and that "usually we'd expect to see panels lasting years and years".

They are a reputable company to be fair, so I believed their 'we stand by their product' spiel.

Although the panel was just outside of its Warranty period (24 months) they honoured it nonetheless and are currently arranging a replacement to be dispatched - happy days.

Big thank you to everyone on this thread who helped out, couldn't have done this without you!

One thing that did puzzle me a little bit - the Supplier told me that generally Semiflexable Solar Panels don't really have all that much longevity. They said that their 24 month Warranty is sort reflects the life expectancy of the panel!

Seems odd as they previously said they expect them to go for 'years and years'... Unless that actually means... 2 years haha!

So question - Was I expecting too much from a semiflexable Solar panel in that it would last more than 2 years?? The fact that it's boned to the roof gave me a the impression that it would be a fairly permanent fixture? But if in fact it's only got a couple of years before it's Brown Bread (so sayth the supplier) seems a bit daft attaching it to the roof of the vehicle no!?

Thoughts, as ever, always welcome

 

[TallPaul_S]

Semi-flexible panels do tend to have a lifespan of a few years on average. You only have to do a search on here, we get a member with a failed panel or 2 a week sometimes it seems!

 

[ginkster]

If you fit the new panel I suggest removing the old one, cleaning the roof then putting a layer of paint protection film (PPF) down before bonding the new one on. This will make it easier if you need to replace it again in the future (hopefully not as soon as 2 years!). The PPF needs to be a bit bigger than the panel with at least 20cm extra on the front edge. I’d also recommend bonding it in a way that gives a gap of a few mm underneath to allow for a degree of air flow and water to escape. Many of the problems are caused by no air gap causing the panel to overheat or trapped water freezing and breaking the panel.