Review on Efficient 50W Solar Panel Kit with Upgraded Charge Controller – SUNER POWER Mono Crystalline Panels, Waterproof, and Versatile 12V Solar System for Car, RV, Marine, Boat, Trailer, Off-Grid Applications by Will Jenkins

I removed the panel, put a meter on it, got 19.87 volts. Controller plugged in, yellow light on (minimal docs doesn't explain what that means) Controller output was only 4.3 volts! Connected to the battery for charging, the light went out. Numerous emails to the company (they don't have a phone!) went unanswered after five days. Item returned to Revain. Revain refunded me on the day UPS received the excellent package, even though the money was on a Revain "gift card" and not returned to my credit card. to me after the return is completed. They genuinely wanted to make things right. They sent a (free) 20w panel/controller kit and asked if I would like to double check. I agreed. The set arrived yesterday. I'm setting it up temporarily, following the instructions extra carefully. They are not written by an American and unfortunately something is lost in translation. The battery used was a bit low, 12.6V. I connected the controller to the battery FIRST and then the panel to the controller as instructed. I checked the voltage on the battery again and got 12.73V which means charging is in progress. It was around 11:30 a.m. with winter sun (low on the horizon, the panel is vertical and not optimally positioned). So it works. I wish for a further voltage increase and will check again tomorrow and the day after tomorrow. Ideally it should be in the 13V range, indicating the battery is fully charged when trickle charging. I will also check for battery voltage drops after cloudy days (blocking diodes should prevent this). It seems that in order to use an item like my tractor to charge it, I have to unplug the panel from the controller and then unplug the tractor from the controller. Not very comfortable. I think you could leave it connected to the controller the whole time and be careful (read responsibly) not to short out the output. I suspect my problem with the first panel kit was a bad controller as only one LED was lit and it was a dim light. yellow. All LEDs light up as expected. I changed my rating from one star to four. If we get to 13V after a sunny day and there is no voltage drop after a cloudy day, I'll pull up another star! Edit 2: 12/18/2019 Suner was disappointed, I couldn't give a better review and they (Mason) were determined to do the right thing. It seems the controller I got was bad and the new one worked as expected. The paperwork with the panel is not clear, the problem lies in the technical letter from China to the USA. Also, an email sent is likely to be answered while you're in bed at night, so the troubleshooting process can be lengthy. But I can assure you that they will take care of you. Patience. My battery is now fully charged (13.7 volts floating) in mediocre sun. Here are the key concepts. The battery should be slightly charged, 11.5 volts or better (less is essentially a dead battery). First you need to connect the battery. In this case, the controller "calculates" the battery voltage (12 or 24 V). After a few seconds (two indicators light up), the indicators will change and you can connect the panel. Then, after a few seconds, all three indicators light up. You are in business! If you disconnect the battery (like I do, this is tractor maintenance) you need to follow the procedure. The controller is disconnected from ALL. Connect the battery, wait for two lights to light up, connect the panel, all three lights up. Suner deserves five stars!