5W Mono Crystlline

This is the second one I purchased, they work as expected keeping the battery topped off.

Something drains the battery in my truck. If I don't drive it for a week, it will be dead. I don't have time to hunt down the drain so I purchased this, as I don't have any outlets near where I park it. 1 week later my truck starts right up. It has been cloudy and a few days it was covered in snow and this still kept the battery topped off. I am super impressed! My one complaint is that the solar panel does not disconnect from the cord at the solar panel. Not a big deal, but I have to open the hood to disconnect it.

Great solar charger for the cost. For the first 6-9 months in the weather it works as designed but after about the 9 month mark the solar charger starts to loose the ability to push a full 4.5-5 watts. After about a year I was only seeing 1.75 watts. But for the price and the durability I have replaced them with the same brand every year. 4 years in a row and they are still my goto. The only manufacturing upgrade I could recommend is some type of sealer around the plastic and the top of the panel. Over time I believe water finds a way in and starts to cause issues with the board inside.

These work great on my jet ski batteries! Ensures a solid start. Plus I added a deadman switch that disconnects the negative terminal from the ski circuit.

I've had alot of problems with car batteries. I don't drive much anymore and the battery looses power. Since I put in this charger, I have had no problems. I hang it in the south facing passenger window and plug it into the cigarette lighter. Never have had a problem since. Some chargers won't produce enough wattage if inside the car. I tested this device with a volt meter and only lost half a watt by putting it inside the car.

I used this on my second car in the hopes of maintaining the battery pending a sale, and ended up having to replace the battery because this was useless and the battery died. The car was parked outdoors in full sun all day, every day, but the charger did not manage to produce enough power to keep the battery alive. The wires are also the cheapest quality possible. I snagged one accidentally on the trunk, and it snapped in half with barely any force. AVOID.

Since my retirement, I do not drive my vehicles (two of them) enough to keep the battery charged. I came across this solar solution and ordered one to check the quality. I was very surprised and pleased. It was easy to install, I was able to connect it using my cigarette lighter plug since the plug operates when the car ignition is off. So far so good! I have since ordered two additional devices, one for my second vehicle and one for my husbands vehicle. My husband has an antique vehicle so the cigarette lighter does not operate while the ignition is off, so I simply attached the battery clip connector to the solar panel connector and placed the solar panel on the windshield inside the car, and since the wiring is so thin, I ran the wire through the hinged edge of driver side door and under the hood of the car and clamped the battery clips to the battery, with plenty of wiring remaining. This keeps the solar panel out of the weather! I will keep you posted as to its durability and longevity, but so far, no dead batteries!

Most of the time, these seem to keep 12V car batteries charged up, but even with constant direct sunlight, every so often it seems to drain the battery instead of charge it.. I've got 2 of these 5W units installed on vehicles I don't drive much and stay parked outside. Not sure what causes them to flake out and drain the battery every so often but it happens, and then I have to jump them. Not as reliable as a battery tender that is plugged in to line power.