SUNAPEX 20W Flexible Solar Panel with MPPT Charge Controller, Solar Battery Charger Maintainer, 12V Waterproof Solar Trickle Charger for Car, Motorcycle, Boat, Marine, RV, Trailer, Tractor,Truck, etc

It works wellI've had this panel for a little over a year now, the 20 watt version.I keep it hooked up to a truck that doesn't get driven as often as it should. It's got some small parasitic loads, like a dash cam and remote start system.The truck will kill the battery if it isn't started once every couple of weeks or so. This panel stuck to the south facing windshield and plugged into the cigarette lighter works great. I could probably hook it directly to the battery but this is easier to use that way. Just unplug it and take it in the cab with me. The suction cups hold on well if you get them wet first.It does have to be on the outside of the window to do any good. Windshields block UVNo complaints at all from me. Still works well and my remote start says my battery is sitting at 12.8 volts as I type this. It certainly won't charge a dead battery, not very fast anyway. But it will keep it full.

This 20W solar panel has proven to be a reliable power source for my Meshtastic node. The built-in charge controller is particularly valuable for this application, preventing overcharging of the battery without needing additional components. I'm getting consistent power output even in partial shade, which is crucial for maintaining node uptime in less-than-ideal locations.The panel's physical construction is appropriately weatherproof - I've had it outdoors through several rainstorms without issues. The included mounting O-rings are sturdy and make it easy to secure the panel to poles or other structures. While the cigarette lighter adapter isn't particularly useful for Meshtastic applications, the alligator clips work well for connecting to standard battery terminals.For Meshtastic users specifically, I found the voltage output to be very stable, which helps prevent node resets. The 20W capacity is actually more than needed for a basic node setup, but this overhead is helpful on cloudy days or when running additional sensors. You'll want to add appropriate connectors for your specific battery setup, but the included wiring is of good quality and easily adaptable.One minor consideration is the somewhat limited length of the included cables, so factor in some extension wires if you're planning to mount the panel any significant distance from your node. Also, while the frame is sturdy, you might want to add additional UV-resistant coating if deploying in extremely sunny locations for long-term installation.​​​​​​​​​​​​​​​​

I like the fact that the connections are the longest one I could find about 6 to 8ft.Mounted on outside wall and connection to an ATV inside works with some to spare.6 months later the battery started right up, 3 months later the battery is still fine so no over charging... Good product this is my second one due to 2nd vehicle...

I purchased this solar panel kit after I found out my car battery was draining because I wasn't driving enough. I was a little skeptical at first but ready many reviews. I put this in the back driver side window as my house faces north east. It gets great sun and tops off my battery. Now my car starts right away and strongly! Nice design with suction cups to mount to your windows and I only had to wait 1 day to see a difference in the way my car started! Decent charge speed, basically trickle charge. Easy easy easy to use. Just find an outlet that is always on and plug it in.

This has kept my battery healthy despite almost all of my rides being 3 miles or less. I think I get more compliments on it than I do my actual motorcycle.

Originally to get the immediate use from these (I ordered two), I simply attached the cigarette lighter connector to the panel and plugged it in. This worked perfectly. So recently I decided to use the direct battery connector so I could just unplug the panel when I didnt need it, but when I went to connect it, I noticed the red wire (positive) from the panel was connecting to the black wire side of the direct battery connector plug. This would result in battery current flowing backwards through the panel. I know this as I have a good sized solar setup on the house going to batteries. The lighter plug seems to be wired correctly as red connects to red. In all the other plugs for direct connection to the battery or the alligator clips to the battery, the connection would be red to black, which would be a bad thing.I could simply reverse the direct battery plug to connect the black to the battery positive and red to the battery negative, but people who dont know may find themselves dealing with a direct short, possibly burning up the panel or worse. I suppose most people would use the lighter plug connection, and that seems to be the only correct one, but I do wonder about the others. i did verify this with a multimeter as well, the panel is putting out 17 volts, and red is positive.