Bests & Worsts Reviews from Amazon

Good panels but cloth may have UV issues. PWM charge controller is OK but does not provide max output. If this came with a MPPT controller I would have given it 5 stars. I purchased this item thinking I might have to send it back due to questions I had relating to it's quality and output. 330 watts with PWM controller for a little over $300 seemed like one of those "to good to be true" deals. I decided to give chance and ordered it in early November. After 2 weeks of snow and clouds, I live in south western Michigan, I finally got some sun today for testing. One of the things that I was looking for in a portable solar panel was one that had the newer ETFE coating in place of the older, glossy, coatings that I have seen peel off in other reviews. This model, FFSP-330W has the ETFE coating and improved solar cells. I ordered ASIN B07JPH4PHG and expected to receive the 330 watt solar panel. When it arrived it came in a box that said FFSP-320W. There was a small sticker on the side of the box showing that this was the ASIN B07JPH4PHG. I emailed DOKIO asking about this to make sure that I received the correct panels. They replied within one day and with one more email exchange with pictures they confirmed I had the correct unit. Having read that PWM chargers are not the best I also ordered a Renogy ROVER 30A MPPT charge controller to compare the output to the DOKIO PWM charge controller. Here is how I tested the panels and charge controllers. I used two plastic saw horses from Aldis to prop up the solar panels at 30 deg angle for the low sun in Michigan this time of year. I also looked up the expected power from the sun given location and time of year and found that it is 1/4 to 1/3 of what the summer sun strength would be. I took a 12v marine battery and hooked up both charge controllers along with a 12v heater that drew 11A. I set all this up so that I could move the panel output from one controller to the other rapidly to compare output. I also put an Amp meter on the battery to compare panel output to what the charge controllers said. Note that the ambient air temp was 40 deg F. I was thinking that since the sun power was 1/4~1/3 the normal max strength that I would be lucky to get 6~7 amps. With the DOKIO PWM I measured ~13V with 14A, 12A according to the clamp on meter. With the Renogy MPPT I measured ~13V with 16A, 15.5A according to the clamp on meter. Using the Renogy values I was getting ~200W. The MPPT was definitely performing better than the PWM. Then I decided to check the output with the panels flat on the ground. By this time there was a haze across the sun and the MPPT output had dropped to 10A. Placing the panels flat reduced this output to 3.5A. BIG difference. These panels are not as small as some of the fold ups but are perfect for storing in my RV and only weight ~15lbs. I am VERY pleased with the panels. The PWM charge controller is OK, nothing special. In regards to the material, RED edge piping, deteriorating over long exposures, that has yet to be determined. I plan on buying some U/V protectant spray to coat the material and slow down any damage. I would recommend these panels to anyone looking for a portable system but you should purchase a 30A MPPT charge controller. PWM controller that comes with the panels is only 20A. If you only lay the panels on the ground you will probably not exceed the 20A . If you angle the panels you will go over 20A. Also note that heat reduces the panel output so if you leave it laying flat on a surface in the summer it will heat up more compared to raised panels that can dissipate heat out the back.