I’ve e-mailed the supplier (Photonic Universe), but I’m not expecting much help from them, while I build up the disposition to tackle removing one of the panels and have a closer inspection of the junction box. Alternatively I may just put the cover back on and continue with the jobs I was supposed to be doing while on compulsory annual leave. Thanks all.
I hear what you’re saying Paul but bear in mind I live in France and the panels were delivered by Amazon.co.uk to France. And the order was 2½ years ago. Referring to the Sale of Goods act and sending a Notice Before Action letter would be a waste of time – me against Amazon, who do you think would win? I’ve put this down to experience and written off the costs. My report of the faulty Eco-Worthy 100w Monocrystalline Semi Flexible Solar Panel is still on Amazon (top critical review), and I’m not the only one to have failed panels. One- or two-years life seem fairly typical for these panels, or less if they’re used in sunshine and they get hot.
I've heard too many reports of flexi panels failing after a very short time to recommend them to anyone now. I also know of at least one installer of solar panels on boats who will refuse to install them for this very reason. The idea behind them is good, but they just don't seem robust enough. Framed panels for me every time now, despite their increased weight and bulk. Just so much more reliable.
Definitely worth watching, unfortunately I didn’t watch it before buying the Eco-Worthy semi-flexible panels.
I think part of the problem is that you can only bend semi- flexible panels along one axis, over a large cylinder in effect. Any surface that curves in two directions like the ends of a bus roof, or most surfaces on the top of a boat means that there is stress built up on the panel. Fixing it too securely may cause it to buckle, fixing it too loosely and it flaps. My panels have thin lines of sikaflex across the short axis of the panel every 30cm ..and are fitted on a fibreglass Devon flat roof cap, no ridges. I was running out of PU glue and in any case that was recommended for fixing. In other words not stuck down firmly but not flapping about either. The individual solar cells also have fairly substantial copper backing which I am not sure that cheaper panels bother with. I would never have bought Solbian as mentioned at the end on the video, but they were originally purchased for a boat as " best in class " .. so I really couldn't say no to free ones with corrosion. I also think my panels are a bit down on output, but it has not been summer time since I finally invested in the MPPT controller last December.
Thing is on a Devon pop top ive really no choice but to fit flexible panels as the ridged ones are to heavy at 8kg each x2 id have to prop the roof up. I only have the standed springs do you think the up rated ones from JK would hold an extra 16kg? Sent from my SM-G960F using Tapatalk
It's not really possible to fit a rigid panel on a Devon concertina type roof. I tried as I had one already. Also this MPPT thing is a bit of a con in that you only gain if your battery is pretty discharged, at other times that extra power is no use whatsoever and spilled off as heat.
In the old days they used to shunt regulate solar panels. Now all they do is reduce the output current of a series buck switchmode regulator to zero which has the effect of reducing the heat dissipation to zero. Both PWM and MPPT do this, the difference is the MPPT actively seeks the point of maximum power transferred from the panel, effectively a variable "transformer" while the PWM just regulates the current average by turning on and off a switch. In reality, theres not a lot in it. Usually the difference is that in the £50 to £60 you pay for an MPPT compared with £15 for a PWM, some of the price goes towards not using the cheapest conmon-positive/switched-negative junk that means even with "load OFF" indicated on the control panel, if you connect a load to the load pins, its still ON because theres a PCB track straight from battery + to load +. Switch is in the load - side. OK for a solar cell and a battery and a light in a chicken shed where there is no negative chassis around the place.
True about panel. Im looking at putting a 100w framed panel on a small roof rack in front of our Devon poptop. Looks like it will just fit. MPPT can gain a fair bit extra power, but depends on panels. If panel max power voltage is close ro charging voltage, it won't gain much. On our boat, the panel max power voltage is around 30v so MPPT gains us quite a bit. Take a 100w panel as an example, if max power voltage is 22v, then with MPPT controller, you'll get 7a @ 14v for battery charging, if PWM on the same panel, you'll only get 4.5a for battery charging. A 66% increase by going MPPT vs PWM. That's just example numbers, but fairly typical of some of the panels I've been looking at for the van. Obviously each panel and installation will produce different figures. Also, neither controller dissipates excess power as heat. It only draws the power required from the panel up to the limit the panel can produce. If the requirement is for less power than the panel can produce, the controller just doesn't use it.
MPPT controllers do have a gain in current because the 100 watt panel putting out 5 amps at 20V will only delive about 5 amps at 14volts through a PWM with a particular sun intensity. Or 70 watts. The switcmode in the MPPT, even without power tracking can deliver about 8 amps by acting as a constant power transformer between 20V/5A and 12V/8A. The MPPT only really cuts in over a fairly narrow range of operation, where the open circuit cell voltage is still high but the current available is reduced from full- sun. It does just abour manage to produce something even when my series stack of panels is down to 16 volts.. a bright overcast day, then its about 0.1 amps into the battery. MPPT controllers are worth having because being more expensive, generally they are made to a proper specification rather than churned out to a price. And you get the option of Bluetooth to an app or wired connection to a remote display panel..
I have changed the springs this weekend on my Devon using the JK uprated springs £37 inc postage last week. And my poptop with two 100 watt semirigid solar panels bangs up now, rather than sort of slopping around and blowing back down in a Force 5.. That story is on the gas struts for poptop thread. I started replying there, realised what was wrong with my bus and made that the next sub-project.
Temperatures 1700 on 22nd of April. Solar panel exterior 45 degrees C . White roof exterior 37 degrees C Under solar panel headlining 43 degrees C. Under white roof headlining 41 degrees C. Poptop had been up all day. Air temperature inside bus about 32 degrees C...
Mike can you put some pictures on showing how you've attached the panels and what type they are please. Sent from my SM-G960F using Tapatalk
Solbian SP100 .. currently at about £600-£700 EACH !!! Fixed with four lines of Sikaflex across the roof, basically one on the leading edge, one on the trailing edge and one at 33% from the front and another at 66% from the front. The paint is peeling at the back with water ingress under the paint around the pop riveted panel replacing a Devon roof vent, the Sikaflex is not helping .. The black goop is sealing bolt heads .. I will be doing some sanding and repainting soon. These survived when I was doing 60-65mph and the poptop got ripped open in the bow wave of a truck doing 55mph which I was overtaking into a gale.
D'you honestly think Mike paid that ?? He loves a bargain , and these were better than bargain-ous... Sent from my SM-G960F using Tapatalk
