15W 12V Solar Battery Trickle Charger Maintainer, Built-in Smart MPPT Charge Controller, Waterproof 15 Watt 12 Volt Solar Panel Charging Kits for Car Auto Boat Marine RV Trailer Motorcycle, etc

I keep this inside my car, with the wire running out of door and under hood and attached to battery just like a small set of jumper cables. The solar panel attaches to window with VERY strong suction cups.It has a cigarette lighter attachment, but on most American cars you can't use cigarette lighter because when engine is off so is that. (I've read on some pick-up trucks this will work.)Before this, the battery died every 3-4 days of not using car. This keeps it charged and I can start up car.Only once did I have to jump start, and not sure if it was the winter weather, or wire connection maybe moved just enough to be out of place. Overall. I'm glad I got it.

The media could not be loaded. Got so tired of running extension cords or removing the batteries to keep them from dying. This thing even works with overcast.I can understand the complaints about the red and green lights, but just know that when it's green, it's ready to go and when it's red, it's hooked up to a battery and charging it. Goes back to green when fully charged (see my wet picture). Makes sense to me.I tried to show in the video that it was slowly charging the battery, even on a cloudy day.I found it easy to use, but I know how to open a box and plug a couple of wires in 😅and connect them to the battery or the cigarette outlet if your battery is difficult to get to. Also comes with a 3rd set of wires if you wanted to hardwire them into to something that needs the sweet sweet solar juices.

Purchased as an on-board charger for a vehicle that sits a lot. After about six months it has zero voltage output in full sun, the green LED flashes "okay" but there is no output. It will not move the needle on my multimeter. I have other brands of solar chargers that are gong on five years old and still kick out the voltage to maintain a full charge.chineseum junk. Caveat Emptor!

Had one on a class A motor because I didn’t want to keep starting it up and running the gas low. This came in so good for the purpose of keeping the chassis battery alive. Like it so much, I bought another for my truck in jamaica. You won’t regret it

Not too keen on the suction cup setup. I'd prefer that they were permanently attached and not adjustable. But once it's setup it's been charging perfectly.

I bought this to keep my grandfather's old truck battery charged. We only use the vehicle once or twice a month and the battery always seems to be near dead, especially in cold weather. After Installing this unit in the truck, the battery was strong in just two days and since then it has remained strong. I was first using the supplied battery clamps - running the wires under the hood. But I tried the cigarette lighter attachment (also supplied) and it works great. Now the unit is inside the truck and out of the weather.This product works fantastic, the user's manual is well written, and the construction seems high quality.I recommend! Enjoy!

I had this hooked into a cigarette lighter and around noon in bright sunlight sitting on top of my car, my multimeter was reporting ~460mA via current clamp and measuring voltage at the harness while connected showed 12.6V, so ~6W? This is at 0 Celsius ambient in sunlight with no cloud cover and after adjusting the panel orientation to get the most current. I initially tried having the panel in my car but it didn't seem to be able to pull much without moving. I don't think it is actually possible to get 15W off this panel and saw other reviews getting maybe 500mA. A positive is that I can indeed see that it's not applying 15V+ to my battery due to the regulator and it is waterproof as I've had it sit in rain and snow as a test; however, I'm still kinda disappointed in its claims compared to its capabilities. This panel really should not be advertised as 15W given the low current produced. I think it'd be acceptable as a 9W panel.

Put this on my utv for a dual battery system and it has kept the batteries fully charged. Very happy.