Sunway SolarCar Battery Trickle Charger & Maintainer 8W 12V Waterproof Solar Panel Power Charging Kit for Car Automotive RV Marine Boat Motorcycle Truck Trailer Tractor Powersports Snowmobile

I purchase this to keep our forklift battery charged when not in use. Does a great job.

so far these haven't disappointed me..i said "these" because i like them a lot that i bought 2 more..so i have 3 sitting in my car feeding my batteries on it..

[update 9/2020]Okay so you got that part about the polarity is crossed between this unit, and a unit like Battery Tender?I'm not getting into who is 'right' or 'wrong' on these things, but the cross over plug is cheap (and the seller even offered to send one, so check with them) ... and they need to resolve that.... however...I need to upgrade my rating - because once you get past making it work, it seems to work quite well...!I've had this plugged in (once I got the crossover) to my Battery Tender pigtail that's connected to the battery of my motorcycle. Without this, I would plug the Battery Tender in when it was getting hard to start... and then I'd forget... and then I'd be buying a new battery. I can't really string a power cord to the carport all the time... So, this might have happened to me, err... more than once? (There's a reason I was looking for this product, right?)This has really worked to solve that problem... the solar panel sits near the bike... and it's not really in direct sunlight all that much... but even with all the crazy distractions of the pandemic (me not riding for months), the bike is now happy to start every time!(Of course this DIDN'T stop the problem of me needing to get out and ride, but at least the battery isn't dead, right?)So I'd still be delighted if they'd work out this need for a crossover plug (if you have the "conventional" Battery Tender), but it sure worked well in my situation. (Much better than the BT solar model I tried to get working - that got recycled. wasted my money).Best of all, I gave in and ordered a second unit for another bike - I think it's worked so nice, maybe I can stop buying new batteries for that bike, too?So I'm obviously sold... and the vendor offered great support (even if I didn't take them up on it) and I'm quite happy with the product! (Well, except for the polarity, but now that I'm forewarned, I can deal with that...)Buy it, sort out the plugs and polarity, and once it starts working it's great.-----------It looks like a great product... put it in the sun and the dongle with the LED lit up...But after reading their notes, and then looking at the cable, I can see why they caution not to connect to existing cables!After using Battery Tender (and a few clones) I have a pigtail already hanging off my battery - but the polarity of this "charger" is backwards!I can just see the design argument... (Yeah, well the battery is the source.... no the charger is the source... no, the... <PTZZZ> ... crud, we need a new charger, and maybe a new battery!)Really, I don't friggin' care, but if I plug this into the existing pigtail I'm going to make a mess and nothings going to get charged.So, cool product, but they cabled it like it's the source (battery) and not like it's charging the battery... so if you're not going to use the supplied (nearly useless) connectors, then get your voltmeter out before you plug it anywhere.

I would recommend this

Great value

Just after the return window closed, I finally went to use my truck which I don't drive that often. I pull the panel off and try to start and the battery is dead. No working. Great.

Was skeptical at first but I installed it on my she'd to keep my mower charged. Solid construction, even came with a test mudule. It works...very well.

Works as advertised worth the money