Solar Problems

[Richard10]

I have bought a Troopy with flexible solar panels installed and a CMTP002 solar controller. It doesn't look like the most expensive thing in the world, but in the land of it'll do, it may do. However, I'm getting ZERO volts from the panels on the controller. Moving instead to the junction boxes, which are packed with silicone, I'm getting ZERO Volts from them too. I am assuming that the panels are knackered, although they don't look in bad shape at all . . . barely even a scratch on them.

My concern is that when searching for new ones, at this site here for example, they specifically call out:
- Do not wire the flexible solar panels in parallel or in series to avoid damage or shortened lifespan
- Do not glue the panel on top, either mount with a velcro attachment or else. Leave a space underneath for the back panel to breathe

Now looking at my panels, someone has most definitely glued them. No idea if there is a gap under them but they look pretty affixed to me. Thoughts? Suggestions? New expletives I haven't come across?

 

[StarCruiser]

Are those fixing bolts that are through the panels at the cross over points metallic and through to metal underneath Richard?

If so, and ifvthey aren't manufactured fixing points, they may be shorting the panels. This may not have damaged them electrically but may affect their sealing if they've been drilled during fitting.

 

[Richard10]

Had wondered the same thing but think the cells connect in series vertically and horizontally, not diagonally....BUT what the hell do I know?! ha ha it is certainly possible they could be shorting. Think they are metallic and unsure how far they go down - the panels sit on a foam which itself sits on fibreglass so they shouldnt be touching metal . . .

 

[Gr8Yota]

Usual recommendstion is to fix down with something like Sikaflex seslent/bobder so can’t see why you wouldn’t glue them down, thatks how they are fixed to boats etc.

As for whether they are working, try using a meter across the panel wires to check. I set up a couple of panels, one for my own use, the other on a camping trailer, this using a cheap controller, works 100%. From your pic the panels look in reasonable condition, better than my one which is working fine so maybe a broken wire or solder joint somewhere?

 

[Richard10]

Think the last guy was worried someone would steal them, which given where I intend on taking the vehicle, that may not be bad advice. Certainly living in Melbourne I have come back to see a footprint on my bonnet before (I was outraged!). I like the sound of Silkaflex, will have a look. As to the solar panels themselves, when you said "a meter across the panels" as in the junction box like in the pic or somewhere else?

I'm getting nothing off of the voltage on the junction box so assume some connector is broken somewhere - will try to take the remainder of the sealant out of that junction box to see if I can actually see the positive all the way through. Next stage I guess would be to remove the entire thing so I can look at it in detail...which I really don't want to do. Really hoping there is a quick fix somewhere as, as you say, the panels are actually in pretty good condition.

 

[Gr8Yota]

Sorry meant to say across the wires.... Should see typically 18V ish and current depends on the sun.

Spelling correction...Sikaflex..

 

[Richard10]

Well am currently getting 0V, Id love 18V! will see if I can take one of the panels off to test if its got any loose connections at the front. After I get all the silicon out of the junction box as id be gutted if the problem was there. There is a diode I think within the junction box, assume that is a diode, so i should be getting voltage before and after that regardless if thats broken or not

 

[StarCruiser]

There's two possibilities for 0v, a break or a short. So test with them disconnected.

 

[Richard10]

Would assume that a beep test would detect whether the circuit is broken or not...which leaves me the option of taking it apart and seeing if there is a disconnect at the back..although, can you see that (or even do anything about that) with flexible panels?

 

[Gr8Yota]

You’ll not be able to see much even if you get them off. Mine delaminated and the whole backing sheet peeled off...still not much to see or that you could do. If it’s not an obvious wire into the juction box then you might end up having to replace them. Can you access the wires going into the controller? Have you tested them there?

 

[Richard10]

Yeah thats what I feared - that it wont give me any access at the back. Its the junction box or nothing i think...but if that doesnt work i'll have to remove the panels anyway. Yeah i checked at the controller, thats what started the whole operation . . .0.77V. At the junction box though its 0V. Once I get the silicone out i can see if there is anything loose in there...hopefully...although it has to be lose on both panels which is pretty mental. I dont know if having the flexible panels permanently stuck down would impact them? Do they need air curculation st all?

 

[StarCruiser]

Have you tested each panel in isolation Richard? By that I mean each complete panel disconnected from anything else but verifiably intact and undamaged cables?

 

[GeekOKent]

Have seen a few people with solar panels stuck onto their front hood.

 

[Richard10]

Have you tested each panel in isolation Richard? By that I mean each complete panel disconnected from anything else but verifiably intact and undamaged cables?

Yes for one, the other looks in the same condition but will test it anyway once I can get to the junction box. I had a chat with the technical team that supply the flexible solar panels in the first place and they asked whether the panels were glued and said that'd be the problem (as I suspected in my first post on this thread). Essentially what has happened is that the guy before me installed solar panels which were working fine (apparently) but as they got exposed to the sun, they got too hot and since no air circulates underneath them, micro-fractures started to appear and poof, there goes $500 worth of solar panels. It'll work initially but over time they'll break. A lesson for everyone.