Flexible Panels, Mounting Methods and Heat

[Eddy]

you can also just buy the MC4 connector online....

https://www.aliexpress.com/item/MC4-Con ... autifyAB=0

Thanks Bagmaker - These might work better for the panels I am working on as they will be roof rack mounted and have to come off car at end of each trip

[Barboots]

The fixings:

So only 12 months down the track I'm again chasing low output from my flexible panels. I have only properly tested one side of the van, but with one side covered I'm getting a full 3 Amps from 2x100W panels in full sun on a mild day [emoji849]

Drilling down on this, one of panel tests as totally dead under load and the other is doing probably about two thirds of what it should.

The cause? I don't know but I think this time it is fracture from movement. There appears to be hairline cracks in the panel, travelling through several cells. I think it's not sufficient to have only the six mounting points retained, plus a windbreak on the leading edge. I suspect that the panel has been able to "flap" a little bit as the wind passes over it. Interestingly the panel with the most cracking is the one performing best.

My thoughts right now are to remove the panels and Thermoclear, convert the working ones to portables, and fit 4x rigid panels to the roof in the conventional fashion. The caravan will then need a small diet to offset the weight increase.

Cheers, Steve

[Barboots]

Some interesting reading:
https://www.solar4rvs.com.au/buying/buy ... -failures/

I was wondering what their solution was, and found this:
https://www.solar4rvs.com.au/solar-inst ... ies/tapes/

I'm not sure having the majority of the cell area unsupported is a stellar idea. Furthermore, the pictured arrangement would not appear to deal with the large amount of heat-induced flex of many caravan roofs which are installed "floating"... so considerably movement of the panel could still be expected. If this is the best solution industry has come up with then I think flexibles will prove to be a potential money-pit.

Surely there's a better way?

Cheers, Steve

[T1 Terry]

How rigid do those socket head screws hold the eyelet of the panel? We mount them with a piece of triangle shaped aluminium with a thread tapped through it to srew down on the 4mm stud and then a locking nut on top to stop it coming undone. The panel is free to move under the piece of aluminium so it can slide around as required. Since we have added the diodes in line on the positive lead we haven't had a panel fail, had a few fly away because the wind caught under the leading edge of the ones mount up front and actually tore the eyelet out of the panel, but apart from those they all seem to be working ok. We have the one from WA visiting soon so we can check out just how they are fairing, but the 5'er with the 1900w on the top is still going well.

T1 Terry

[Barboots]

How rigid do those socket head screws hold the eyelet of the panel?

Thanks for dropping in Terry, you know I value your assistance.

All the washers are free to spin without force, and the panel has a few millimetres of movement laterally.

I think it is buffeted wind which has killed it. These panels are very close to the edge of the van, and whilst the leading edge of the front panel is protected, there's nothing to control cross-winds. The "most dead" panel is adjacent to oncoming traffic... plus it's windy here and I generally tow close to the legal limit.

Cheers, Steve

[T1 Terry]

Possible but probably a loss of connection in the links between the cells and the backing panel and this will sometime come good after a bit of time in the hot sun, other seem to suffer the opposite, work when the panel is cold and stop when it warms up or gets too hot.
Some of the dead panels we replaced and stored upstairs have come back to life so I'm looking at mounting them on Thermoclear backing panels and making an awning for the front of the workshop. I'm looking at linking them is series and using them to recharge the 240vdc nom. battery pack in my PHEV Prius as yet another experiment to determine other possible applications and potential directions for T1 Lithium to branch out into rather than getting bogged down with caravan and motorhome installs as the only egg in the basket.
The off grid house set-ups we have done are proving very popular, a completely different design as far as the solar goes but using the proven battery and management as the base, so I guess we have more than the one egg in the basket

T1 Terry