Review on 🔌 Coocheer Portable Solar Panel Charger 120W - Ideal for Camping Van, Portable Generator, Power Station, USB Devices, Cars, Yachts - 2 USB Ports & 1 DV Port Included by Travis Showcase

I've recently been looking at various foldable solar panels over 100w for charging portable battery packs like the Prymax 555Wh. I asked a few questions at first, including if it has a built-in MPPT controller, but the answer was no. I liked that this device was small compared to others and attributed it to high efficiency solar cells that claim >25% efficiency. I also liked the USB-C PD 20V output, so I made my decision. The device has arrived and looks high quality. Then I tried to test it... I was a bit disappointed with the panel performance in the Prymax as it seemed to start at around 54W and dropped to zero for 20 minutes. After looking into this, I found that this is because the Prymax requires an input voltage of 21V, not 18V... The COOCHEER 120W solar panel initially outputs more than 21V until the panels warm up , and then drops to around 19.4Q At this point I've resorted to using the USB-C connection to charge the Prymax and using the 20V PD output. It worked, but it should be noted that the maximum USB-C power delivery was 45W, not 60W - this is what the panel shows as 20v2a max. I then decided to learn a bit more about the panel and see if I could verify the claimed result. Over the course of 2 days, I measured both the voltage and the current output of the panel at different times of the day and related it to the current solar radiation. What I learned about this panel: • I understand that this panel is supposed to be rated at STC 120W which means 1000W/m2 and 75F. • I tested it under ideal conditions including days where the output was between 900 and 980 W/m2 with an ambient temperature between 70-78F • So I expected a slight drop of 10%-15% to account for the heating of the Panels to balance under the sun, and then a further drop due to solar radiation of 1000 W/m2. I used 85% for PTC conditions and 90% for solar compensation. That means I should see 120 x 0.85 x 0.9 = 91.8 watts of output power. • The maximum power output I could measure was 69.84 watts. This was at 21.1V and 3.31A, with panels at 75F. Solar irradiance on site at this time was 904 W/m2. This means that I only produced about 75% of the rated power - it looks like one of the 4 panels has failed. • Then I measure each panel independently from the side of the controller panel to the opposite end and see 0.71A at 17.7V, 0.72A at 17.7V, 0.99A at 18.0V and 0 .98A at 18.0V. That means each panel was putting out 12.57W, 12.74W, 17.82W, 17.64W... At this point, I realized that the two panels weren't on the Amount of power worked and most likely the cause of my break in power output was more than 10 watts. the loss. I really want to like this panel. It's a great price, good specs, relatively small, but I don't like the limited 45W PD output and the fact that two panels don't work. I have requested a replacement to get four fully working panels and will see how the second round goes. I will update this review at that time. UPDATE 04/24/20: The replacement panel arrived today and I have re-tested each panel. 20.4V @ 0.973A, 20.4V @ 0.996A, 20.3V @ 1.0A, and 20.2V @ 0.893A. Much better on this panel, but panel 4 is still a bit underperforming. I compared my original 120w COOCHEER panel to this at 4:15pm today, the sun was around 805w/m2. The original panel put out 3.39A at 19.5V, the replacement panel 3.81A at 20.0V, a full 10W more than the first panel for a total of 76.2W. My calculations would suggest I was 81 at the time .6 watts should have seen, 76.2 very close. The discrepancy is most likely due to the lower current in panel 4, which has a crease in the plastic over one of the cells. I ordered another 120w triple panel to compare the power output of each to make sure it was working properly. I have raised my rating to 4 stars based on the performance of the replacement, I will upgrade my rating to 5 stars when compared to the more expensive triple supplement. plate today. I put them side by side and pulled out a multimeter. COOCHEER produced 21.7 volts at 3.37 amps = 73.13 watts. A third brand triple 120 watt battery produced 21.4 volts at 4.96 amps = 106.14 watts. That's why I decided that KUCHIR will return. I've downgraded my rating to 2 stars as there seems to be a lack of quality control due to panel variability and overall performance is not comparable to other 120w panels in a similar price range. I want this device to work and deliver the same level of performance as advertised. Keep trying!