Solar not charging battery, can I make it?

[Andy MacD]

Hi, my current set up is standard 2021 Adria Twin with solar (120w I think), a Sun Control SC300M MPPT and I added a Fogstar 280ah lithium battery earlier this year.

At present the battery is sitting at 65% with a voltage of 13.1 and not being charged. I suspected it was not charging while in France but using fridge etc I was never sure. At home I can test with no 12v loads. The MPPT voltage on GRD to PF1 (solar panel) fluctuates between 13v and 18v. GRD to +BS(hab) is 13.1 and +BM(cab) is 13.1 when tested.

Checking the Sun Control instructions it states that the service battery will charge “if the voltage supplied by the panel is higher than that of the battery. I'm assuming that the controller is moderating the voltage to 13.1v then as that matches the battery it’s not charging, however I want it to charge to 100%. On the page detailing “Charging Curves” LiFEPO4 (I have the jumpers set to this) states Phase 2 constant at 14.6v and Phase 4 maintenance at 13.7v.

Any ideas how I resolve this? My knowledge of electrics is a basic so I’m probably missing something obvious to others.

 

[StillGoing]

Have you checked the fuses in the MPPT controller? One looks slightly different to the other one in the photo.

 

[Andy MacD]

Yes, didn’t pull them but did continuity test them and they’re ok.

 

[Lenny HB]

Yes, didn’t pull them but did continuity test them and they’re ok.

You need to pull them to test them

 

[Peavy]

Check also the 15A blue fuse in the right of your picture.
That's the one from the solar to the EBL.

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[Tigger-Tim]

Do you have any lights illuminated on the SunControl?

Sometimes it needs a reset. Wait until night-time (or cover the panel). Pull the fuse from the panel to the battery (or disconnect the battery). Wait a couple of minutes, and reconnect.

 

[Andy MacD]

Thank all. I’ll have another look today.

 

[Bolti]

Have you a flexible Panel?
Check that it is actually working, I've had two and both have gone in about a year.

 

[FrankNicklin]

Have you a flexible Panel?
Check that it is actually working, I've had two and both have gone in about a year.

I was looking at Flexible panels and have been told that they must still be raised above the surface of the van for cooling. If they are flat to the van roof they overheat and destroy themselves. Can't see the point in flexible if they still need to be mounted away from the surface.

 

[StillGoing]

I had a flexible panel, stuck to the pop-up roof on a T5, for years - never had a problem. Yachts have them and don’t seem to have issues. Maybe some flat panels are much better quality than others.

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[ontheroadagain]

I have found the Sun Control MPPT controllers to be unreliable.
We had a factory fitted one in our Adria which would constantly lock up and had to be disconnected to reset it.
It was replaced with a larger Sun Control MPPT controller when I added a second solar panel but this also proved to be unreliable.
I need a controller that also charges the starter battery so earlier this year I fitted a Votronic MPPT controller and have had no problems since.

 

[FrankNicklin]

I had a flexible panel, stuck to the pop-up roof on a T5, for years - never had a problem. Yachts have them and don’t seem to have issues. Maybe some flat panels are much better quality than others.

5 weeks after installation. Previous set lasted a year.

 

[StillGoing]

5 weeks after installation. Previous set lasted a year.

As soon as I saw the words “includes paid promotion“ I stopped watching.

It‘s fake - she can’t be standing there with a panel on fire if it was real. The panels are glued to the roof.

 

[FrankNicklin]

As soon as I saw the words “includes paid promotion“ I stopped watching.

Of course the image is fake, but the damage to the panels and the RV roof is not.

That was just an example but I have been told the same by installers not to use flexible direct on the roof. Don't shoot the messenger, only passing on what I have been told. Solar panels need to dissipate heat and they can't if they are fixed directly to the roof panels.

 

[StillGoing]

Of course the image is fake, but the damage to the panels and the RV roof is not.

That was just an example but I have been told the same by installers not to use flexible direct on the roof. Don't shoot the messenger, only passing on what I have been told.

I can show you images of fixed solar panels on fire. That’s not to get at you it’s just that there is a lot of misleading information and few facts.

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[Andy MacD]

Ok, getting back to my issue if I may.

I covered the solar panel then disconnected the solar regulator from the main electrical box then pulled the 2 fuses in the solar controller and the 15A one on the electrical box, all ok.

Connected the solar regulator back and uncovered the solar panel and now I’m getting between 0.8A, 9w and 2.5A 22w charge into the battery per the Fogstar app.

So it appears the “switch it off then on again” routine worked.

Next question. Given this is Aberdeen and the sun is low in the sky on this very sunny day what should I expect to get out of a 120w solar panel?

 

[StillGoing]

Ok, getting back to my issue if I may.

sorry

I covered the solar panel then disconnected the solar regulator from the main electrical box then pulled the 2 fuses in the solar controller and the 15A one on the electrical box, all ok.

Connected the solar regulator back and uncovered the solar panel and now I’m getting between 0.8A, 9w and 2.5A 22w charge into the battery per the Fogstar app.

So it appears the “switch it off then on again” routine worked.

Next question. Given this is Aberdeen and the sun is low in the sky on this very sunny day what should I expect to get out of a 120w solar panel?

Good news!

It’s difficult to say how much you should get as there are a lot of variables but I think 2.5A is not unreasonable.

 

[Andy MacD]

Cool, thanks.

 

[Guigsy]

In full Brummie sunshine with very few clouds at roughly solar noon, I'm currently peaking at 60w from a 175w panel.