solar voc issue

[The Ham]

I did post this on another thread, but thought I'd ask the question again.
I've just discovered that a flexible solar panel Which is now stuck on my roof, was sold to me as having a voc of 21.2, during installation the label was taken from the back so the adhesive could bond direct to panel. The following day I'm reading the label and it states a voc of 23.4, I have a CTEK250 fitted.
Apart from my arguing this out with the seller what are my other options/solutions?

 

[Loz]

Buy a Victron controller, the cheapest fix.

 

[Dellmassive]

Good advice from @Loz there.

Got a pic of the solar label?

 

[The Ham]

 

[The Ham]

The label and the website info

 

[Dellmassive]

Yep very odd.

160w panel, but obviously sent out one with a slightly different spec.

The CTEK. Voc is 23v max.

The CTEK can be damaged by PV volts over 23v..... So you run a risk of damaging the CTEK.

It's possible you could run that panel on the CTEK for years with no issues, the 0.4v above 23v might be lost in cable resistance anyway depending of the type of cable and length of run.

Voc max will be under test conditions too.... So you might not even see 23.4v in UK summer time.

Also PV power drops of as the temp rise's.

So you could take a gamble and run it and see.

Or as above just fit a stand alone controller to run alongside the CTEK.


Eg.

Victron smart solar 75/15

So 75v voc max and 15A charge rate max.

https://amzn.to/3OjtIwH

.

 

[Dellmassive]

Fyiw....

Get your multimeter out and test the panel, see what voltage you are getting.

Disconnect the PV POS from the controller..... Then test across both the PV feed cables...

According to the sticker above....

You should see up to... 23.4v voc.

 

[The Ham]

 

[The Ham]

ok, great, thanks for replies.
Its more than the stated 21.2, so think victron is way to go.
so do I just ignore the ctek and wire the victron/panel direct to battery?

 

[Dellmassive]

21.75v is still below the 23v..... So for example at this moment that panel will be ok on the CTEK.

But it's a possible risk ( strong sun and a cold day will increase the voc )

..
Yes , PV panel to the Victron, then battery output to the leisure battery, fused at the battery.

Make sure you get the smart version of Victron, that has the Bluetooth and works with the app .

The blue solar version doesn't have BT onboard.

 

[Dellmassive]

Here's a few examples.

Diagrams, Schematics & Wires -- How I Done It --

Diagrams, Schematics & Wires -- How I Done It -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

www.t6forum.com

 

[The Ham]

Cheers Dell
Ctek currently only fitted in a sort of 1st phase so not linked to solar yet, even though panel fixed to roof.
I do have the Victron battery monitor already, which was to be fitted in the next phase.

 

[Dellmassive]

Awesome.

I have a bmv712 on the van too. They are great ...

..

 

[The Ham]

Thanks for your help, a bit more expense but one less problem for me

 

[Dellmassive]

It's a better solution.

Plus you now have some redundantcy

 

[The Ham]

Plus you now have some redundantcy

?

 

[Dellmassive]

If the dc-dc charger fails for any reason, you still have a solar charger..... And vice versa.

With combined units... If it fails you loose the lot

.

So you now have redundant charge sources.

 

[The Ham]

Ah I see what you mean

 

[The Ham]

So I have a 160w on the roof and a 110 agm which will do me for 90% of the time, but I also have a fold up 120w that I would like to add if needed when off grid for a while.
What MPPT would you recommend ?

 

[Dellmassive]

you can add the fold up with the roof panel to have 160w + 120W = 280w on the same Victron 75/15 controller. . . ( but it will limit the power to about 220w max )



++++++++

to run two or more panels, look at upgrading to the 100/20 Smart unit.

https://amzn.to/3Q6BawF

that will run 290W


++++++++


or if you want to run it separate, you can run it through a separate controller. . .


you can use any you like . .

have a look here: Solar PWM & MPPT Controllers - How I Done It -


personally i would recommend either a Renogy Voyager (PWM) or a Victron Smart (MPPT) .


so :

Solar PWM & MPPT Controllers - How I Done It -

Solar PWM & MPPT controllers - How I Done It - There is a lot of talk about Solar at the moment, and with spring not to far away i wanted to go over the whole Solar controller thing. The main components are the Panels themselves, the charge controller (whether that be stand alone or...

www.t6forum.com

or

a victron smart 75/10 ( smaller unit )

https://amzn.to/3zqhE8A

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