POWISER 1.8W Solar Battery Charger 12V Solar Powered Battery maintainer & Charger,Suitable for Automotive, Motorcycle, Boat, Marine, RV, Trailer, Powersports, Snowmobile, etc.(1.8W Amorphous)

Literally JUST GOT THIS, and wow was installation a breeze.So I'm a long-haul trucker, and in the dead of winter I often come back to a vehicle that won't turn on at -10 thanks to a just-slightly-drained battery. So this year, I decided to get this before winter to keep my battery at peak voltage so I never have to jumpstart my car in the dead of night.And installing it was as simple as tossing it in my back window, and plugging it into the 12v port in my center console (for me, this one is an always-on port, so it will charge the battery with the car off.What surprised me most was that when I attached my multimeter to the plug end (before connecting it to the car!), I was reading 11.1v and .66amps. Or, 7.3Watts. As this is rated at 1.8W, I was pleasantly surprised! And this on a highly overcast day, too. Just wow. High expectations!

I bought due to price. I have it on a 12 volt battery for my deer feeder. I am gone from home for 2 weeks at a time, so I figured this would keep it charged. I was wrong. After a month, battery is barely charged.Ended up buying a different brand from Academy and it works well.

The description in the listing says "POWISER 1.8W Solar Battery Charger 12V Solar Powered Battery maintainer & Charger,Suitable for Automotive, Motorcycle, Boat, Marine, RV, Trailer, Powersports, Snowmobile, etc.(1.8W Amorphous)"But the instructions say do not use as a charger. I hate being deceived. I'll keep it for what it is, but I bought it to charge up a small 12v battery when it got used a bit, not just to 'maintain' a full charge. 2 stars for the description — I have no idea how good the thing is.

First off the good. - It Keeps My Dump-Trailer Battery Charged FullyNot So Good - the suction cups are useless to me.How I made it perfect for me - I bought a couple flat 1 inch or so rare earth magnets with 3m adhesive double sided tape that you can find on Amazon for like 6 bucks, Stuck them on the back of the panel then stuck to the top of the battery box. Holds securely going down the road. I wanted to test it so I went out and hooked the battery charger to the battery and it went to float 5 seconds after I hooked it up so it is indeed keeping the battery fully charged.

I bought these to put on my motor home batteries while in storage. I live in Florida , so we have sunshine almost everyday. Where the batteries are I cannot put suction cups on a window. I attached them to the side of the motor home. It is a smooth flat surface. They fell off in just a couple days. The suction cups are tiny and I don't know how they would stay anywhere for any length of time. Unless I can figure out a way to attach them to something to stay in the sun, they probably won't be much use to me.