100 Watt Semi - Flexible Panel Problems

[tim]

Hi All,

 

I fitted a semi - flexible Biard 100 watt solar panel to the roof of my van using stikoflex back in Easter.

Just come back from two weeks holiday in the van, and had problems with the panel sometimes working, and sometimes not.

 

Checked all connections etc, seemed ok.

 

Talking to someone on the last day, and he suggested that maybe it gets too hot, then cuts out.

Thinking about it, I thought that could be possible, as we left the van early to go on days out, but returned sometimes in mid afternoon, when it sometimes wasn't working, but then it would work later on that day.

 

As I only noticed this towards the end of our holiday, I hav'nt been able to do full checks with the panel etc, and keep the van in a storage yard, so can't keep an eye on it.

I,m away again for a week on Monday, so will then be able to do checks on it.

 

Just wondered if anyone has any ideas, the panel should be still under guarantee, but how I would get it of the roof I don,t know.

 

I know with the rigid panels there has to be a gap between them and the roof, but the idea of semi flexible panels is to stick them to the roof.

 

Thanks in advance,

 

Tim

[Guest Rita]

It will cut out if battery is fully charged . I know some put a bit of carpet on half the panel

[Reads]

if anything its usually the controller/regulator which stops working

[JTQ]

As others are saying are you a 100% sure the panel is at fault and it is not the controller doing what it should and switching off completely once the battery is at full charge?

My Morningstar Duo does this to both batteries; it has quite a bit of hysteresis before it switches things back on again.

Edited August 8, 2014 by JTQ

[brilock1]

I have yet to bond my panels to the roof, what I plan to do is run fairly high ridges of sikaflex or similar along the roof and then gentle drop the panel on it. I am hoping this will then give some space for cooling!

 

If you want to remove the panels use a plastic windscreen ice scraper and gently work your way around the edges until its free enough to peel off. You can use a long knife which is quite quick but you may well scratch the roof!

[tim]

Hi All,

Thanks for replies.

I know that it is the panel at fault as I have two solar panels going into one regulator.

Both panels have a fuse fitted on the positive wire that goes into the regulator.

It is the type of regulator that has a display to read how many amps are coming from the panels along with other readings.

So I can easily see by removing the fuse from either panel to see that the new flexi panel has no power coming from it while my old 85 watt rigid panel has, or when the new panel is working.

 

Thanks Again,

 

Tim

[JCloughie]

Hi All,

Thanks for replies.

I know that it is the panel at fault as I have two solar panels going into one regulator.

Both panels have a fuse fitted on the positive wire that goes into the regulator.

It is the type of regulator that has a display to read how many amps are coming from the panels along with other readings.

So I can easily see by removing the fuse from either panel to see that the new flexi panel has no power coming from it while my old 85 watt rigid panel has, or when the new panel is working.

Thanks Again,

Tim

Still does not conclusively rule out the controller, perhaps one input is faulty. Try swapping the 2 inputs then check again.

 

John

[peterjohn]

To "cut" the panel off use dental floss drawn back and forth in a sawing motion . .........Peter

[tim]

Still does not conclusively rule out the controller, perhaps one input is faulty. Try swapping the 2 inputs then check again.

John

Thanks for replies.

John, the wires from the two panels go into the same inputs. I twisted the two positive and the two negative wires together, then put them into the inputs on the controller.

I would like it to be a faulty controller, much easier to fix, it is about 9 years old, but can,t see how it could be, as I can take the fuses out of both the positive wires going into the controller, and there is a drop in amps to zero when I remove the working panel and no drop in amps when I remove the "faulty" panel.

 

Thanks Again,

 

Tim

[JCloughie]

Thanks for replies.

John, the wires from the two panels go into the same inputs. I twisted the two positive and the two negative wires together, then put them into the inputs on the controller.

I would like it to be a faulty controller, much easier to fix, it is about 9 years old, but can,t see how it could be, as I can take the fuses out of both the positive wires going into the controller, and there is a drop in amps to zero when I remove the working panel and no drop in amps when I remove the "faulty" panel.

Thanks Again,

Tim

Point taken, thought it might have dual inputs.

 

John

[tim]

Hi All,

 

Just an update,

I contacted the UK company from eBay about the panel, they replied asking me for a meter reading of when the panel was,nt working.

 

I did it during last Saturday, a sunny day.

7. 30 am. Meter reading 18. 60. Regulator reads 0. 2 amps.

8 am. Meter reading 0. 67.

8. 30am. Meter reading 0. 35.

3pm. Meter reading 0. 01.

6pm. Meter reading 0. 01.

7. 30pm. Meter reading 18. 54.

 

I did it again on the Sunday, and the readings were between 0. 01 and 0. 03, a cloudy day.

 

Awaiting their response.

 

Tim

[Alan Stanley]

These type pf panels are bonded directly to boat decks and roofs and then subjected to the most extreme testing with people walking all over them, salt and temperatures on the equator, with no ill effect. .

 

Having just had an interesting few hours tracing a fault on my panel when it turned out to be degradation in the insulation on the wires - inside the main protective sheath - of the wire. I would check the continuity of both positive and negative wires from the panel to the panel to the controller. Or run a jury rig wire by passing the existing cable and see what happens. .

[tim]

These type pf panels are bonded directly to boat decks and roofs and then subjected to the most extreme testing with people walking all over them, salt and temperatures on the equator, with no ill effect. .

 

Having just had an interesting few hours tracing a fault on my panel when it turned out to be degradation in the insulation on the wires - inside the main protective sheath - of the wire. I would check the continuity of both positive and negative wires from the panel to the panel to the controller. Or run a jury rig wire by passing the existing cable and see what happens. .

Hi Alan,

 

Thanks for reply.

When I did the meter readings, it was at the end of the wires, positive just before the fuse.

However when I first noticed problems,I made two tiny holes in the wires, just quite near the panel, and stuck the meter pins into them, and got my readings from there, to eliminate any possible breaks in the wires or connectors.

 

Thanks Again,

 

Tim

[JTQ]

These type pf panels are bonded directly to boat decks and roofs and then subjected to the most extreme testing with people walking all over them, salt and temperatures on the equator, with no ill effect. .

 

Whilst that is true the substrate onto which they are typically attached is somewhat stiffer than a half mm thickness of unsupported aluminum sheet that can be encountered in non bonded caravan roofs. Here the bending and flexing is more aggressive than with the film bonded onto a more supportive base. As the crystals forming the panel are brittle by nature they could well fracture where used in applications outside of their intended and tested market?

[tim]

Hi All

 

Latest update, good news!

After receiving my meter readings, the company asked for me to take pictures of the readings.

This I did, then received an email apologising for the faulty goods and asked if I want a replacement or refund.

I chose a replacement, as when it was working it was a good bit of kit, plus I have all the wiring etc, in place for it.

They then said they would send one, which they did, I received it on Friday.

 

However, they have asked for me to return the faulty one, with them paying postage.

I have tried to get the panel off, using a ice scraper and a knife, but it is almost impossible to do, without causing some damage to the roof.

I admit I was very heavy handed with the sikaflex, as I did,nt want the panel falling off the roof.

 

I will contact them explaining this to them, and wee what they say.

 

Tim

[TonyJover]

You could try fishing line tied to two pieces of wood as handles - think Cheese Cutter.

 

That should work its way under the panel without too much trouble.

 

If you don't get it off where will you put the new one?

 

Tony

Edited August 31, 2014 by TonyJover

[tim]

Hi All,

Contacted the supplier explaining how I could,nt get it of, stating that I used sikaflex, they replied saying they have contacted sikaflex to find out if there is a way, and will let me know.

 

Sounds possible Tony with a fishing line with two bits of wood, the big problem is though that I will have to climb up a step ladder to do it, and it could be tricky trying to use a lot of force and hold on at the same time.

 

If I can,t get it off, I have thought about sticking the new panel on top of the old one. It might sound a bit daft, but as the wiring is all in place there, it seems possible.

I admit I was very heavy handed with the sikaflex, in not only putting it on in I zig zag pattern on the back of the panel, but then when panel was on the roof, I went all around the outside with it. Perhaps this is why I had problems with it.

 

I think next time I will just do blobs with it, the size of a 10p piece, just all around the edge, so then maybe some air could get underneath a bit.

 

Tim

[TonyJover]

Hi Tim. Does white spirit soften the Sikaflex?

[dreadly]

I wonder if this stuff would be any good?

 

http://www. ebay. co. uk/itm/Sika-208-Remover-1L-Tin-/201159117986?pt=UK_Home_HomeDecor_Accessories&hash=item2ed6048ca2

 

Found this exert on a boating forum. .. -->

"Contrary to common belief, there is solvent that will dissolve fully cured polyurethane; dimethyl formamide. On immersing the PU in it, it will cause the PU to swell and become a weak gel. DMF is horrible stuff though and I doubt it's available to anyone but a licensed industrial / laboratory user ( it was/ may still be used in printing, the effects on people exposed to it are well documented!).

There are commercially available "PU dissolvers" based on N-methyl pyrrolidone ( "NMP") that are used in the PU industry for cleaning moulds; not as effective ( or nasty!) as DMF though."

Edited September 2, 2014 by dreadly

[fred]

It seems to me sticking the new panel over the old one is the simplest solution. The cheese wire idea seems a great way a removing a panel if you want to swap it onto another van but it seems that you would be left with some sikaflex left on the roof which would be a pain to remove so you can get a smooth surface to put new one on. Sticking it to the old panel you have a ready prepared smooth surface.

[JTQ]

Hi Tim. Does white spirit soften the Sikaflex?

Not in my experience; Sikaflex is a curing product and once cured that is it. The cutting with a cheese wire is the only way I believe you will break the panel free but IMO bonding over the existing panel will give a more flexing resistant substrate to the new panel and a better chance of reliability over time.

[Paul_B]

I would be concerned about the panel overheating if it was stuck over the top of the other.

Most stick on panels need to be stuck direct to the roof so they can use it as a heat sink, some panels are designed to work on grp or wood so it would be advisable to ask the company what they recommend for their panels

[fred]

I wondered about the heat sink aspect of bonding it onto the roof. But then again that assumes a metal roof a fibreglass roof wouldn't be an efficient heat sink. It would interesting to know what the advice of the supplier.

[JTQ]

I would be concerned about the panel overheating if it was stuck over the top of the other.

Most stick on panels need to be stuck direct to the roof so they can use it as a heat sink, some panels are designed to work on grp or wood so it would be advisable to ask the company what they recommend for their panels

Whilst aluminium can be an excellent heat sink, here where it is a thin film backed by hopefully a very effective roof insulation material polystyrene most probably, then it will offer near zero effectiveness as a heat sink. The aluminium itself here has no where to transfer that heat.

So if the panel is marketed for use on yachts that are likely to be GRP then needing a better heat sink is not a requirement. They will of course work more electrically efficiently with a heat sink that does manage to cool the panel, but for yachts that is not often there.

 

As I have said earlier my concerns would be far more that the panel in use has a firm substrate not a continuously flexing thin sheet of aluminium as would be the case in a non bonded caravan roof construction.

Edited September 3, 2014 by JTQ

[tim]

Hi All,

 

Many thanks for all the replies.

I hav'nt heard back from the supplier yet, so will email them again, as we are away the weekend after next and would like to know before then what the score is.

The supplier is basically a large internet shop that sells everything, so would'nt think they have any knowledge on solar panels.

I went to the makers website, Baird, and they recommend sikaflex for bonding the flexible panels.

I,m at present still thinking about sticking the new panel onto the old panel, but as I said using less sikaflex.

 

When I was away in the van and the sun was shining, to touch my rigid panel, it did'nt feel really hot, but the flexible panel close to it was really too hot to touch!

 

Thanks again,

 

Tim