Topsolar 10 Watt 12 Volt Solar Trickle Charger 10W 12V Solar Panel Car Battery Charger Portable Solar Battery Maintainer for Car Motorcycle Boat Marine RV + Cigarette Lighter Plug Alligator Clip

I originally bought this panel with the idea of putting it on my shed roof and using it to keep my lawn tractor battery topped up. My tractor is old and the charging system is pretty much non-existent, but since the battery is mostly used only to crank the engine, I can get through an entire season with it. Almost. The battery, like the tractor, is starting to get a little tired. I've found myself having to take it out and charge it to get through this season. Let's face it, this battery is on its last legs, and I'm just hoping I can get through the next few weeks with it. So I bought this solar panel and immediately ran out of time to install it on the tractor. Instead, I stuck it in my truck. My poor old truck sits unused for weeks at a time. It always starts, but it tends to crank pretty slowly because the battery draws down between uses. This charge/discharge cycle is hard on both batteries and alternators, and both have gotten too expensive to abuse and potentially damage. Since I don't drive the truck much and I don't want to run a battery tender outside, I decided to repurpose the solar panel as a truck battery maintainer. For this, it works perfectly. The panel mounts to the inside of the windshield with four suction cups. Easy to put on, easy to remove when I want to drive. The panel itself is very thin so I have to treat it gingerly. I wish I could find a solution that didn't involve removing it every time I want to use the truck but so far I haven't. We'll see how it holds up over time to being repeatedly installed or removed. I envision flexing it just a little too much and hearing a fatal cracking sound but so far it's been fine. The panel uses SAE connectors which allows you to attach to the cigarette lighter dongle, alligator clips, or dedicated ring terminals. I use the cigarette lighter adapter because the lighter socket is live on my truck all the time. If your vehicle disconnects the lighter socket when the ignition is turned off, you'll have to figure something else out. SAE connectors are hermaphroditic connectors. That means that two SAE connectors will plug together, but the polarity will reverse (IE the "positive" terminal of one will feed the "negative" terminal of the next one). I triple-checked that the panel would not be wired in reverse polarity in my installation. The panel has a reverse-polarity indicator but I prefer to use a multimeter and see for myself. You can get polarity reversing adapters if you need them but I didn't. Last time I went to use my truck, the panel had been on and charging for about a week. The truck cranked just as quickly as if I'd put the battery on a dedicated charger. I haven't checked current output or state of charge of the battery, but my seat-of-the-pants analysis tells me that it's keeping the battery topped up. Impressive considering we've had a few cloudy/rainy days this week. We'll see how well it works over the winter. In all I'm impressed with this panel. It's a simple solution that (so far) seem to work well. It's WAY less expensive than buying a battery so if it continues to work, I will consider it money well spent. I'll update once I've used it a while longer.

I don't drive or go anywhere but maybe once every other week and only for a couple miles. So the electronics drain the battery due to sitting unused. I bought this to hook up to my battery and it does a good lob. Easy to use and hook up and it fits in the corner of my windshield. It keeps the battery fresh like it is new and still have all my electronics to work when just sitting.

It’s a nice panel BUT if you’re going to charge a car battery with it, read this. It uses some power from the battery when there is no sunlight. Using the ammeter on my multimeter, the current is positive when the panel is in the sun (battery is charging) but negative when the panel is not in the sun (battery is being drained). It’s only discharging at about 3 mA so I think it’s only the little green LED on the back of the panel using power. Also the cigarette lighter plug that comes with it has a red LED on it that stays on even when the solar panel is unplugged which uses some battery. Now before you decide not to buy this, know that the amount of power 2 little LEDs use is insignificant compared to how much power the panel collects each day but just to let you know, the battery does discharge slightly overnight. I wish the LEDs wouldn’t light up when there’s no sunlight. It’s still a great panel. My battery now starts the car quicker now that it’s topped off every time I start. I also use this panel to charge a power wheels battery for a portable solar power bank. Only other downside is the panel gets very hot sitting in the sun but it looks like they make a 20 watt one with a white backing that should stay cooler.

I've had a few times where I came out to start my car and the battery was dead, But that was because the dash cam had drained the battery. My power port never shuts off even if I turn the car off. The only way to turn it off is to disconnect the battery or pull the fuse. And it's a Wi-Fi – cam so I was searching for a Wi-Fi hotspot and on top of that it's always recording, It never stops. Show you this. You just ate a lot of power. With this trigger charger, it has just enough juice to run the dash cam without it draining the battery completely. I've been able to leave it for 5 days and have no issues. Used to be only about 2 days and I couldn't start my car. I haven't tested it beyond 5 days cuz frankly I'm tired of asking my neighbors for jumps. But it works great. It's full of power via the power port because yes I have two of them. I mean why wouldn't you always be on in a car?.. It's actually one of the many things here that works as advertised. I haven't been a meter to it yet, but I think it pushes a bit more than 10 w in direct sunlight, but considering my car is usually parked beneath an awning, it still provides enough power to power the dash cam and keep the battery charged so that it'll start whenever I need it. So it was a great value. Definitely worth the money paid. And I would definitely recommend it. The only issue is it does get quite hot sitting in the sun but it is black and I live in Arizona, those are two things that do not get along. If they can make it white it'd be perfect.

Works great, will be buying more. This is installed on top of a metal ROPS cover on a mini excavator for battery management. Time will tell how it holds up in Southwest Florida sun/rain, but so far its specs for output are good. Sealed controller helps since it’s in the weather, only concern is the vibration from the excavator and if it will hold up to the shaking.

Charger works when sun is out, however when sun is not out the charge controller does not prevent the reverse flow of power so it winds up draining the battery when not actively charging. Son in summer time it kept my battery charged but in winter when there was more darkness than daylight it actually drained the battery.

I purchased 5 of these over the last 3 years. I need to maintain a charged battery in several dinghies. A lawn tractor battery powers a bilge pump to keep the vessels afloat. The module on the back of the panel doesn't allow the suction cups to adhere to a flat surface. The module is too thick to permit clearance. They keep the batteries topped off, though. After a couple years the clear coating on the panel has degraded. There's only about 30% of the surface with any glossy film left. I'd like to find out from the seller how to repair this but I haven't found a way to ask them a question. Polyurethane? Acrylic PSA film? I assume they applied that coating for some protection...

Got it today and put it right to work. Even though it's overcast, it still charged my motorcycle battery. It was smaller than I expected, about the size of a car license plate. It included handy hardware both to connect it and even suction cups to mount it in an out of the way place. I'll provide an update when I've had a little more time to evaluate how well it maintains the charge on my battery.