This is the fourth one I have purchased to trickle charge rv/auto batteries. I have noticed that if the solar panel is placed on the dash of vehicle, behind windshield glass, it will tend to NOT over-charge the battery. If placed outside of vehicle, in direct sunlight, it will tend to sometimes over-charge the battery. For this reason, my rv battery solar panel is the only one I run with a small solar panel charge controller made by Battery Tender.

We have a couple of cars and a tractor that are used once every 2-3 months. It was always a gamble if they would start or if the battery would be dead. Living in Colorado, the cold would also kill these batteries even faster. We have one of these on our Dodge 2500 diesel, and it keeps the battery full and it starts up every time without issue. Same for our tractor. The solar charger keeps the battery charged. For our purposes, the cord length is no issue. I like the quick disconnect on it because I don't have to open up the hood on our tractor to take the solar panel off when I use it.Overall, this is a great product, and the value has more than paid for itself. We've had no issues with these products being outside in the weather. We live at a high altitude where UV light is extreme and we get lots of snow in the winter. These live outside in those elements and hold up just fine. Its super easy to hook it up to the battery, the quick disconnect is super convenient when its time to use the vehicle, and the suction cups & straps on the back of the solar panel make it easy to stick wherever it needs to go. It stays on the windshield of a truck just fine, and it attaches to the steering wheel of our tractor just fine.

I have tried this in many different areas of use. Tested power output to see if it creates power when I need.When I place inside my window of van, it does Not generate any power, tried in in three different vehicles, and it does not work in the vehiclesIt only works when placed outside, in direct sunlight. When the sun did not hit the panels, it produces less that. . 02w of power.So most days when clouds are about it's pretty much useless. I have another cheaper solar panel that works anywhere all the time, even in heavy shade, and generates power everytime. I don't recommend this product.It works but only in a very selective way. Not worth the money, better units can be got for cheaper that work all day no problem

I will follow up with a more detailed review in a couple of weeks. But, right out the gate, this looks like a very nice kit. Several different options for connecting to your battery. I am going to order another to use on my boat.

I got 2 of these & have used them on dozens of vehicles over the last 2 years. It even brought back to life a nearly dead 5 year old battery. I use them mainly to maintain cars I don't use frequently. The connection options are very handy, though I'd prefer slightly longer cables for larger vehicles I have parked to avoid sun in the windshield. Nothing a pair of jumper cables doesn't resolve, though. Obviously, the output is based on placement & sunlight but I've never had them overcharge a battery or fail to keep one charged.The only problem I've run into is strong wind will overcome the suction cups so they need to be better secured if you're expecting wind more than 20mph. I now just secure them every time I put them out, not relying on the suction cups.

Nice to keep the battery topped up were ever the car is parked and not having to start it for weeks or months.

Portable and works as it should. My dad has a forklift that sits outside most of the year and it gets cold and won't start. Using this solar panel when parked we hook this up and it has started everytime!

I went through a period this summer where my car wasn't being driven very often, and while I didn't run its battery all the way down, it definitely went far lower than I would like. Since we live in an region of abundant sunshine, I figured I'd add a small solar panel to top up and maintain the battery when the car wasn't being used. We have a Renogy 200W panel for emergencies (intended for charging a Bluetti LiFePo4 box) that we're happy with, so I figured I'd give one of their little panels a chance.First impressions: the panel itself seems reasonably well built. it's stitched into a fabric housing with flaps that fold out that have suction cups whichhold it on the inside of the windscreen. The fabric makes handling it much safer than a plastic or metal case as it doesn't get nearly as hot in direct sunshine and doesn't transfer heat to your hands nearly as badly.The panel connects to one of a number of cables with a SAE connector. In my opinion, these cables are the weak spot of the whole thing.The main option for a quick connection has something like a 5-foot cable with a pair of alligator clips that you'd clamp on the battery terminals, which is *way* too short to be useful. Given it's not completely waterproof, it has to be mounted on the inside of the windscreen, and in my car the combined length of the panel's cable and the extension does *not* reach the battery in the front of the engine bay, meaning either another extension or custom cabling is required in my case.The panel also comes with a SAE to cigarette lighter adapter, which is useless for my car. My outlets are not powered when the ignition is turned off, so this is of no use to me. Finally, it also comes with a short cable with a pair of eyelets that you'd bolt to a battery with side terminals. It's about 2 feet long, so presumably this is for charging a battery outside of a car.None of these cables are fused in any way; I'd be especially cautious of using the eyelet cable wired permanently to a battery; if something shorts, there's no way to quickly remove it from the battery the way you would with alligator clips, and there's no guarantee you'd get the SAE connector apart in a hurry. In my opinion, the hardwire eyelet cable in particular must have an inline fuse right at the battery end of the cable on the positive side, but Renogy cheaped out.I actually ended up using the eyelet cable to make a custom cable. I cut the eyelet off the positive side and stuck the wire on the end of a usual add-a-fuse tap thing that runs to an unused always-hot slot in my inside fuse panel. That allows me to connect the panel up when I need it, but remove it at the SAE connector and tuck the wire away when I'm not without needing to connect and remove the car side wiring.Otherwise, the panel appears to work well enough. Starting from a bit below 12V, it dragged the battery up by a little over a tenth of a volt per day and kept it there when I went back to use the car after a few weeks. You wouldn't want to use one of these to completely charge a battery from flat; it's way too low-power for that. However, for this specific application, a larger, higher-output panel is not needed. Again, we get a lot of sun and this was tested at the beginning of summer, so it may not be nearly as effective in more northern locations at other times of the year.

I had this over a year on my van to maintain the battery. The solar panel sits on the dashboard all day long under the minimal San Francisco sunshine. After about 2 months, the suctions no longer sucks....or rather it sucks. After about 6 months, the fabric began to disintegrate, leaving black dust like ash all over my dashboard. If this was in a sunnier state, it would have worn out a lot sooner.I think if they used more durable fabric and better suctions, this would be a better quality product. Also, an option USB connector would have been nice to make the panels portable to charger mobile devices would be nice. Other than material quality, the panels works well and kept my battery charged.

Two stars - because it functions.My main concern is for a product designed to be exposed to the sun, it really doesn’t like being exposed to the sun. This unit has been sat on my dash (inside the car not exposed to the external elements) and due to the sun it’s slowly degrading the material on the outside. This doesn’t affect the operation but as you can see from the pictures it leaves a lovely fine black dust everywhere it goes or whenever I touch it. Cheap and nasty.

No se requiere conectar el auto para mantener el acumulador cargado