cheap 'lensun' solar panels???

Remember that a brand importing panels needs a margin of about 30% above landed cost to make money and promote the brand and much more if they sell through retailers.

The ebay offerings are just direct or semi direct sales cutting some of this margin out. So not always inferior products. Buyer beware of course.
 
I agree all the positive things said above. My experience with 'cheap ones' from Seateach is all good.

Some 85% or more of all the panels are made in China. They are batch tested. Ones with lowest failure rates go out as to quality at top prices through top outlets, then lower grades go through lower channels of course. Cheapest ebay direct from HongKong are probably the least reliable but still not bad.

Rigid panels, usually mono-crystalline, are capable of the highest output, in the best conditions but do not like shade or poor light. They are also very breakable and need their own dedicated space for their rigid frames.

Semi-flexible amorphous panels are slightly lower output, much more tolerant of shade and poor light. Shade from the boom, or low light morning and evening will still work them, though not so well of course. They can be mounted on slightly curved surfaces and you can walk on them or drop things on them.

You do need a MPPT controller to get the best results. Panels work at 19 to 21volt and much of the available power is dumped by poor regulators in bringing the output down to 14.1v for battery charging. MPPT controllers do not do this, they reduce the voltage but increase the amperage so as to maintain the wattage output (I think). This increases the charge to the battery. Low light is stepped up to 14.1v, at lower amps of course, but still charges into the evening. Some MPPT suppliers cost a lot, I did ok at Midsummerenergy.co.uk.

Cheers.

Mike
 
dmmbruce said:
I agree all the positive things said above. My experience with 'cheap ones' from Seateach is all good.

Some 85% or more of all the panels are made in China. They are batch tested. Ones with lowest failure rates go out as to quality at top prices through top outlets, then lower grades go through lower channels of course. Cheapest ebay direct from HongKong are probably the least reliable but still not bad.

Rigid panels, usually mono-crystalline, are capable of the highest output, in the best conditions but do not like shade or poor light. They are also very breakable and need their own dedicated space for their rigid frames.

Semi-flexible amorphous panels are slightly lower output, much more tolerant of shade and poor light. Shade from the boom, or low light morning and evening will still work them, though not so well of course. They can be mounted on slightly curved surfaces and you can walk on them or drop things on them.

You do need a MPPT controller to get the best results. Panels work at 19 to 21volt and much of the available power is dumped by poor regulators in bringing the output down to 14.1v for battery charging. MPPT controllers do not do this, they reduce the voltage but increase the amperage so as to maintain the wattage output (I think). This increases the charge to the battery. Low light is stepped up to 14.1v, at lower amps of course, but still charges into the evening. Some MPPT suppliers cost a lot, I did ok at Midsummerenergy.co.uk.

Cheers.

Mike
Click to expand...

good stuff, thanks for all that. the top of my coachroof is mildly curved so the semi-flexible seems the way forward. again, partially shaded by the main boom too so you're points above are noted. I think im going to give the 80 watt one a whirl.

question about the regulators. one way of charging two battery banks, starter and domestic would be through 2 diodes. voltage drop not normally a problem as solar panels usually say 18-20v off load. however if I tried the same technique downstream of one of these regulators -single output to two battery banks- then I guess the voltage drop across the diodes would confuse the regulator? would it?

can you get two output channel ones?
 
dmmbruce said:
I agree all the positive things said above. My experience with 'cheap ones' from Seateach is all good.

Some 85% or more of all the panels are made in China. They are batch tested. Ones with lowest failure rates go out as to quality at top prices through top outlets, then lower grades go through lower channels of course. Cheapest ebay direct from HongKong are probably the least reliable but still not bad.

Rigid panels, usually mono-crystalline, are capable of the highest output, in the best conditions but do not like shade or poor light. They are also very breakable and need their own dedicated space for their rigid frames.

Semi-flexible amorphous panels are slightly lower output, much more tolerant of shade and poor light. Shade from the boom, or low light morning and evening will still work them, though not so well of course. They can be mounted on slightly curved surfaces and you can walk on them or drop things on them.

You do need a MPPT controller to get the best results. Panels work at 19 to 21volt and much of the available power is dumped by poor regulators in bringing the output down to 14.1v for battery charging. MPPT controllers do not do this, they reduce the voltage but increase the amperage so as to maintain the wattage output (I think). This increases the charge to the battery. Low light is stepped up to 14.1v, at lower amps of course, but still charges into the evening. Some MPPT suppliers cost a lot, I did ok at Midsummerenergy.co.uk.

Cheers.

Mike
Click to expand...

Yes I have had cable and connectors from Midsummer Energy & they used to sell inexpensive framed monocrystalline panels on ebay, I had one of theirs on last boat and it was good, not sure if they sell them any more though...
 
dom said:
But that was old technology back then ;););)
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They seem to sell both the older metal backed semi-flexible panels and the newer generation of fibreglass backed panels. One odd thing is that Lensun are still selling their fibreglass panels on eBay and seem to have stock available. The Italian company have theirs marked as "Product not in stock" but they will take orders.

Previous post is saying Lensun can't sell them here but they are still doing that and at a lower price. Perhaps they are lower quality but I'm pretty certain they are coming from the same factory. Both panels seem to be very similar but ones from Italian company have a different junction box. Pictures of Lensun ones show same junction box they used a year ago.

The post mentions lower quality with low spec. cells but doesn't say that's what Lensun are selling. Then mentions problems with customs inspectors not letting panels through and Lensun keeping the money. Very odd situation as no feedback issues, no stories of non-delivery and Lensun still selling. Anyone else think that this is a bit odd?
 
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Yes. I've had a couple of Lensum panel (metal backed) I've been pleased with them and have had no issues with quality, payment or customs. I think they said UK despatched, they certainly were delivered quickly.
 
thalassa said:
2011 thread. Things might have moved on a bit....
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Yes, but Blacksails is talking about the newer fibreglass backed panels. His first link goes to an Italian company selling the very similar ones to Lensun (but not in stock). Post #36 is saying that Lensun can't sell these legally. It appears that the thread was revived to show a problem with the latest panels.

However, the second link to the Italian company does show older style metal backed panels (they have these in stock).
 
ghostlymoron said:
Yes. I've had a couple of Lensum panel (metal backed) I've been pleased with them and have had no issues with quality, payment or customs. I think they said UK despatched, they certainly were delivered quickly.
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Yes, that's why I thought the mention of problems with customs was very odd. Lensun sent a panel to S. France last year and I'm pretty certain it came from UK stock. No problem with French customs officers either.
 
Thanks, starting to make some sense now. I was thinking of buying another semi-flexible panel and boat is in Sardinia so Italian supplier makes sense. Lensun panels seem a bit larger then they used to be. That means efficiency has dropped, unless they've put a larger border around the cells (unlikely).

Not a lot in it on price between Lensun and Quooka. Main issue for me is that Lensun have stock but Quooka don't at present.
 
BlackSails said:
Maybe contact them (qookka) for understand when they will restock otherwise if you need them asap you have to choose Lensun. Anyway has you can see on their new panel isn’t with back contact cells (sun power) because you can see the contacts on the surface

View attachment 62401 .



In these cells, sunpower, you can not see the contacts. (rear)
View attachment 62402 .

In fact, the difference is 17 cm less in length for FLY Solartech of Qookka
Click to expand...

I must be missing something. The Lensun panels I got last year (1 in Spain, 1 from UK) both look the same as the picture you show. The connections were in a square, sealed, box on top of the front face.

The other manufacturer uses a long thin box mounted in the same place with connections at either end. Putting the junction box on the underside wouldn't make much sense.

Perhaps you are talking about the connections between each cell. Unfortunately, the pictures were too small for me to see that detail. Other Lensun pictures I've seen do look the same as pictures of my existing panels in that respect. Not certain that the pictures really prove anything as Lensun could well be supplying something not exactly as shown.

Thanks for the update. I'm not in a rush for a new panel so have time to contact the Italian company regarding delivery to Sardinia. I might not have noticed the change in size of the Lensun panel quite so early so thanks for the heads up on change of specification. The new Lensun 100W panel might be too long for my needs. I was considering 2x50W anyway, only 20 Euro more but better shading performance. Another plus point is that too much flexing will break the cells and the 100W panel is pretty long and floppy. The shorter 50W won't suffer as much and also have smaller cells. Light and stiff is better than light and bendy as I'm fitting them on an awning.
 
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BlackSails said:
Exactly, the new panels of lensun, just because they can no longer use Sunpower are bigger as you can see in their website. Regarding the pictures I was not able to zoom into the picture, but if you pay attention you see that those from qookka are “made" by a single color on the surface (because they have silver contacts on the rear of the cell) in the other photo of new Lensun panels (The ones that you've purchased in the past are like the ones I took myself with sunpower cells like those of qookka, but they could not sell) you can see the “streaks" that are precisely the contacts that i mentioned. Anyway, I hope you can find an appropriate solution! Good luck and good wind
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Oddly, I just found one link on Qooka that went to an 80W panel with same spec. as Lensun when I bought my first panel and they have it in stock.

http://qookka.com/en/stand-alone-pa...-80w-12v-antireflective-for-rv-and-boats.html

I considered buying it and then noticed that the pictures were just like my first Lensun panel. It had very thin silver connections clearly visible on top. It failed in 5 weeks with a hotspot and was immediately replaced for free with a better design. The replacement had much wider connections between cells but were not visible. The silver connections were covered over or ran behind the cells.

Panel I have and others I've seen after that did not have silver streaks visible on the surface. They looked like mine and had the connections hidden.

One eBay supplier (lensunsolar85) does show a picture with the silver streaks but the others don't. I think that the eBay Lensun suppliers are the same company. I previously contacted two when they were short of stock and realised replies were from the same person. Doesn't look as if most are supplying panels with silver streaks you mention (e.g. lensunsolar2010). If fact, I've just noticed one advert from lensunsolar85 with silver streaks and another without any. I think they are just using an old picture in some cases.
 
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I look upon solar panels as 'disposable' ie they won't last forever however I've never had to replace any.
Incidentally, it's odd that the 30w panel from photonicunivers is cheaper than the 20w.
 
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