Well the alleged 200w panel has arrived and the results are in.

The construction seems very sturdy. Packaging was good and delivery was easy. The plugs seem good and the free anderson to 4mm plugs and cable seemed ok. The only thing was the gauge of the wire from the panel doesn't seem very thick.

Before I plugged the new panel in I ran my old 80w panel and it was producing 75w 4.5a with a touch of cloud.

In better conditions I then plugged in the new 200w panel. With midday sun 21C it's maxxing at 105w and 5.8a with peak v18.2. No that's not 200w....

Interestingly the sticker on the back had all correct information but no amp or watt information just max V etc. The box was the only place it claimed 200w.

I've requested a return (which they can't refuse) and await to see what if any information or response they provide.

You've done very well there to accentuate the positives before outlining the shortcomings. Trust you get a suitable result out of this.

Everyone is well up on solar but thought it might be of interest to link this site with a mine of information...............

www.redarc.com.au/solar-faqs#10

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slammin said..
Well the alleged 200w panel has arrived and the results are in.

The construction seems very sturdy. Packaging was good and delivery was easy. The plugs seem good and the free anderson to 4mm plugs and cable seemed ok. The only thing was the gauge of the wire from the panel doesn't seem very thick.

Before I plugged the new panel in I ran my old 80w panel and it was producing 75w 4.5a with a touch of cloud.

In better conditions I then plugged in the new 200w panel. With midday sun 21C it's maxxing at 105w and 5.8a with peak v18.2. No that's not 200w....

Interestingly the sticker on the back had all correct information but no amp or watt information just max V etc. The box was the only place it claimed 200w.

I've requested a return (which they can't refuse) and await to see what if any information or response they provide.

This time of the year is always hard to get maximum watt. I think in the summer you would see more the 180 watt.

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southace said..


This time of the year is always hard to get maximum watt. I think in the summer you would see more the 180 watt.

Yeah I don't think so though because I'm in Cairns so pretty much ideal. My 80w panel was putting out it's full 80w.

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slammin said..

southace said..


This time of the year is always hard to get maximum watt. I think in the summer you would see more the 180 watt.

Yeah I don't think so though because I'm in Cairns so pretty much ideal. My 80w panel was putting out it's full 80w.

It's the angle of the sun. If you face the panel directly to the sun you see the watt increase. Most 200 w pannel fitted flat may only get 80 to 100w at this time of year .

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southace said..

slammin said..

southace said..


This time of the year is always hard to get maximum watt. I think in the summer you would see more the 180 watt.

Yeah I don't think so though because I'm in Cairns so pretty much ideal. My 80w panel was putting out it's full 80w.

It's the angle of the sun. If you face the panel directly to the sun you see the watt increase. Most 200 w pannel fitted flat may only get 80 to 100w at this time of year .

The sun was overhead and slightly North and the panel was tilted accordingly.

getting a cheap, efficient, long lasting solar panel is a bit of a lottery (even more of a lottery with flexible panels).

more detailed information on the variables can be found here:

www.cleanenergyreviews.info/blog/best-quality-solar-panels-manufacturers

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slammin said..

southace said..

slammin said..

southace said..


This time of the year is always hard to get maximum watt. I think in the summer you would see more the 180 watt.

Yeah I don't think so though because I'm in Cairns so pretty much ideal. My 80w panel was putting out it's full 80w.

It's the angle of the sun. If you face the panel directly to the sun you see the watt increase. Most 200 w pannel fitted flat may only get 80 to 100w at this time of year .

The sun was overhead and slightly North and the panel was tilted accordingly.

Fair enough but I can see your mppt charger has actualy gone to absorption for the first time in four days and is getting close to 14.4 volts float so obvosly better. How can you find there actual wattage? If not 200w panel we should take them to consumer affairs.

We've been under a massive cloud and rain band for a week, south of here had 500mm in 24hrs . Today was the first sun so a good opportunity to see how it went.

The fact the 12yr old 80w was putting out it's stated maximums shows that the conditions were ideal. In terms of how to find the actual wattage I think I did. I think it's a 100-120w panel. It's similar in size to the 80w.

This discussion is being covered on another site and the suggestion there is that the size of the panel is a better indicator of wattage. 1sqm receives 1000w of sunlight and good panels capture 20-25% maximum wattage so 200-250w. So 200w at 20v is 10a/sqm .

Back in my original discussion the Low Energy Development 200w panel is slightly larger than 1sqm but it's efficiency isn't amazing at only 17%. The Outbax panel I have here is 0.7sqm so assuming the best made and very very expensive panels efficiency of 25% the maximum it should theoretically produce is 175w at a more realistic efficiency of 17% it maxxes at 120w. That figure is more inline with my testing today.

As for consumer affairs they have to give me a refund through eBay anyway so there's nothing I can do but others who've bought under performing panels can raise it with their retailer.

Reading some more the efficiency for a monocrystalline panel is at best 17-19%. Thanks for reminding me Fishmonkey.

I bought the GIARIDE panel because the width was perfect for allowing me to put two of them side-by-side on my SUV roof. They were easy to install and generate a ton of power on the go. They easily charge 3 car batteries during the day and keep my 12V refrigerator going no problem. They flex just enough to conform to the curvature of the roof but are stiff enough they won't just blow around in the wind. Surprisingly good panels, hopefully, they last through the winter months up there on the roof.

It is very important to count the number of cells in any solar panel before purchase, ignore any labeling as a "12V solar panel".

Most rigid panels are 36 cells:
Max power output is around 0.5Volts/Cell ie. Max power at about 36x0.5 = 18V.
Open circuit voltages will be up around 0.6Vots/Cell ie Open circuit volts about 22V
They should deliver close to their rated power only if operated at the max power point (18V) on a cool spring day.
Older style controllers will loose a little pumping into say a 13V battery voltage.
A max power point controller should be loading the panel at around 18V and under the right conditions you should get close to rated power regardless of battery state.

Many flexible panels are only 24 cells: (Many "ebay type" suppliers might cut and paste their specs from a 36 cell panel.)
Max power output is around 24 x 0.5 = 12V.
Open circuit voltage is around 24 x 0.6 = 14.4 V.

Mostly they are intended as a cheap lightweight solution to charging camping batteries and the like via a direct connection and with no intervening controller. Used in that way it reasonably matches the characteristics of automotive type batteries delivering full power into a low state battery (11-12V) and yet not seriously overcharging it if left on for too long (14.4V).

The upside is that the 24 cells panels are usually physically smaller and lighter, but it is a big trap for the unwary.

If you use an old style controller (which depends on the panel voltage being somewhat higher than a fully charge battery) you won't see full power into the battery because the panel will be operating well above its max power voltage. Some max power point controllers will also struggle to deliver max power because their design assumes an input panel voltage higher than the output battery voltage.

Many "outdoors" style forums all full of disappointed rants from flexible 24 cell panel buyers claiming "Chinese rubbish" when they don't properly understand the specs & proper usage. Some blame also for the selling store because many are not across the 24 cell vs 36 cell difference, with both often being generically labelled as "12V solar panels".

I think "southace's" picture from his 21st May post shows a mixture of one 36 cell (9x4) panel (top) with one 24 cell (6x4) panel at the bottom. Not sure how they are connected but there will be some disappointment somewhere.

Important Lesson: Count the number of cells to know exactly what you are buying. Sometimes this can be hard but usually with large panels each individual cell will have four distinct "corners" where it is cut out from a round grown silicon crystal.

Where I am, I seem to get much better results over the winter than in the summer from the solar panels. I attribute this mostly to the loss of efficiency from the panels getting hotter in summer and also the greater chance of shadowing from the rigging et al with the sun being higher overhead.