Sunforce 52013 1.8-Watt Solar Battery Maintainer (Pack of 2)

4:16 PM 2/21/2011 I bought the twin panel kit Sunforce #52013, 1.8-Watt Solar Battery Maintainer, (Pack of 2) for $34.95 - Sold by: Amazon.com. This is two of the Sunforce #52012 panels. Two at a better discounted price! And they have the little blue LED light that blinks and shows brighter as the more sun hits the panel (I like that!). I love these panels and you women who are looking for a great present for you sons, husbands brothers or fathers, THIS IS SOMETHING THEY WOULD REALLY LIKE. Why? Because if they store their motorcycle Quad or tractor or anthing with a 12 volt battery in it, out in the garage or shed or anyplace where it gets real cold... then most likely they have to buy a new battery every year or so. If you hook one of these solar battery maintainers up to the battery, you can get many many many years of good service out of the battery. I bought a solar charger 20 years ago from Harbor freight that is 1/2 the size of this Sunforce unit and was 3 times the money. I hard wired that into my Ford Van and the battery in that van is about 15 years old and cranks the engine right over even when I haven't started it for 4 months during the winter... because the solar battery maintainer unit keeps the battery HAPPPY ! ~:-) It's like a serotonin in the brain thing. Today was not a real bright day here in the mountains of Arizona. The skies were hazy & lazy. As the sun was shining through my 1/4-inch glass window pane, I held the panel at a perfect angle in my hand so that the sun light was beaming right down in a direct path onto the panel. I watched as the current amperage coming out of the panel went up and down depending on how I held the angle of the panel in reference to the sun tilting the top of the panel back and forth and also twisting and turning the panel from left then to right. Its almost like tuning into a satellite signal, you just keep tweaking it until you find the sweet spot ! ~:-) I hooked up both panels one at a time to a 12-volt battery and then using the Low Current probe hooked to my Vetronix MTS5100 Lab scope and using the graphing multi-meter application I TESTED and measured the current (amperage) going through the wire to the battery. I got: minimm: 0.02amp, maximum: 0.08, Average: 0.07 amps and even 0.02amps when the clouds were blocking out the sun. These are great test readings. It will probably be higher than that when I check it on a day with full Arizona Sunshine on it. I feel sorry for you chumps in the cold hazy cloudy day after day after day areas of the USA ~:-) This is a nice unit and I did buy a tube of the best GE clear silicone and I am going to put some blue 3M tape on the glass about 1/8-inch away from BOTH sides where the glass meets the plastic and then put a bead of silicone between the pieces of tape to weather proof the panel. After the silicone dries then I will take a razor blade and cut the silicone where it meets the tape and then remove the tape. I'll also put a little silicone around the electrical in-out rubber/wire area on the panel, so I can put it up on the roof eve during the summer. During the winter my window in garage gets full southern exposure so that is nice. This unit came with a 8-foot cord that is hard wired to the solar panel and on the other end there is a male/female rubber type connection. I am going to either crimp or solder in an extra 25 feet of 18 gauge copper speaker wiring so that the wiring will be long enough to make it to where I store my bike and truck in my garage (which is not heated). The ONLY problem with this unit (which is easily fixed in a couple minutes) is: 1. The wiring on the connector that is on the end of the wire that comes out of the solar panel and also both 'adapoters wiring connector ends. You need to cut the rubber connector ends off about 4-inches away from the end strip the wires bare and then using a couple 18 gauge butt splicer's reverse the wires and then crimp them. 2. Then you need to do the same with the other two ends on either the #1 cigarette plug cable wiring or #2 the wiring cable that has the red and black clamps. Why did I do this? Because on the solar panel wiring end connector it doesn't make any difference if the exposed metal portion of the connector touches anything because there is protection built in to the solar panel to protect it. However !!!! on either adapters: #1. Cigarette lighter wiring adapter or #2. Battery clamps' wiring adapter, the exposed metal portion of the connector will cause a spark or burn up the wiring if it touches your battery or vehicle ground while either the cigarette lighter or the battery clamps are hooked to your battery or vehicles electrical system. GOT IT! ? Also you can unscrew the tip from the Cigarette lighter end AND BE CAREFUL because there are 3 things inside.... #1. A spring. #2. A 0.5amp fuse. #3. The little tip end. And they will fall out on the floor or ground if you are not careful and I hope you can find them as I did when that happened to me ~:-) I am going to cut the "cigarette lighter" part off that wiring adapter and then splice in a fuse holder with a 0.5amp fuse and then crimp on a couple of `Loop Ends" so I can attach the loop ends directly to my motorcycle battery bolts. That way all I have to do is disconnect the two solar panel wiring end connectors from each other and start my bike or truck and then GO! ZOOM ZOOM ZOOM ! ~:-) And you chumps in china who say your building a rocket ship to go into space.... if you can't or will not understand and fix little problems like this... well lets just say... I don't think you'll make it in space. And oh by the way... your new stealth fighter plane you were showing off to the world on TV... well I got news for ya'. We got a 500KV laser that can burn through 200 feet THICK of metal per milli second. That will take out missiles that fly faster than you can even imagine! You have a good product here, but... You can, and you need to do much better. Later... Rob~O

These are an excellent idea for keeping a lawnmower, boat, car, motorcyle, ATV, or anything with a battery charged when not in use. That would be, if they worked. I ordered them for a car and a motorcycle. The first box I opened the cable into the panel was broken, disappointed. The second one wasn't broken but never had the blue "charge" light come on. Took apart the first one and repaired the broken lead and it works. The other one has a bad cell. Send in a return option to Amazon and they sent me out two replacements even though I said I only needed one, easy mistake. Of those two, one is half the size of the other and works...and the larger one that is the size that I ordered didn't work. So out of 3 identical items, none worked. The one that did work out of the box is the smaller one which pulls about 7vdc in good sunlight. The bigger one I repaired pulls 22vdc. The others make no power at all. The package is cheap and styrofoam, it DOES come with a few connectors and suction cups. The cases are a cheap metal and are apparently pre rusted around the bolt hols and where the suction cups go. For 20 bucks a pop, I wasn't expecting much...but I assumed they would at least work. Props to Amazon for handling the return quickly.

Originally tried using some cheap trickle chargers from Harbor Freight that cost me less than $10 but you get what you paid for. They just didn't work. Don't waste your money on cheap trickle chargers. My wife has 2 Ford Mustangs and only drives the older one because she parks in a very crowded parking deck. Let's just say her car get hit from all sides almost weekly. Her pride and joy is her 2005 Yellow Ford Mustang V6. It sits sometimes for up to a month before getting driven. The first couple of years owning it everything was fine but about 2 years ago it started letting us down. We would go out to take the car out to the store or for a drive and it would be almost dead. I would have to jump start it to get us going but it was fine after that. It could sit a week or so and still start. About a year ago the Mustang started getting worse. It wouldn't even make it overnight sometimes before the battery was almost completely dead. The CD changer would cycle over and over again. (long story short, we never found what the electrical problem was). So I decided in the recent months to find an alternate method of keeping the batter alive without a house electrical device. I was going to try a disconnect switch but that would mean we would loose the radio presets every time we disconnected. I did some research and found that some people were having great luck in using Solar Battery Maintainers. I have been using this solar charger for about 3 months now and it has not let us down. I was surprised that even on cloudy or rainy days the solar panel still blinks and charges. The Mustang has sat for up to 2 or 3 weeks and it starts right up now. I am very happy with our purchase and the bonus is we got 2 in this package shipped for $36 so I can use the 2nd one on another vehicle which right now might be our 19' Boat.

One unit was defective. Output of one unit was only 1.25 volts in bright sunlight. The other unit had a fairly stable output of 18.5-20 volts under same lighting. However the unit had a large swing in voltage output which constantly changed moment to moment under cloudy conditions. With low light condition voltage could be 12.3 volts and 2 seconds later it could be 4.7 volts. Received replacment units. Both units have constantly changing voltage under low light condition. According to SunForce this should not be happening. Under bright sunshine voltage is stable at about 21.5 volts. Both units appear to be able to maintain battery charge.

Product seems to do exactly as advertised. I have a car that sits idle for weeks at a time and this is great for keeping the battery charged. Blue LED light shows that the panel is receiving enough light, but there is no indicator to let you know if the charge is actually making it to your battery. I guess you just have to have faith that it's doing it's job. I believe that this has solved my dead battery issues and it was a great fix at a great price.

Got these, on first arrival one did not work because of manufacturing defect, one of the Cells had stain underneath glass but visible. There was no electricity at all. I give Amazon 5 stars for their service! I had the items delivered in my hotel where I was staying for just one week in the US. The day i received these items, i called Amazon. The helpdesk told me the remplacerent would be delivered the very next day at no costs, and it was! I just had to ship the other ones free off charge back to Amazon. Thats why Amazon would have gotten 5 stars. Wen i was back in Europe i wanted to test them. After placing the suction cups on the panel i placed it on the glas of the rear shield of my car. Unfortunately the suction cups released from the window and the panel fell on the floor, and the glass of te panel broke and rendered the panel useless! So these panels cannot stand any drops, they will break. I have one panel left and must find another method to keep it in place, since the suction cups are useless! This is why i give 2 stars for the product. If the suction cups where better quality the pannel would not have fallen down. If the pannel was rugged, it probably would have survived the drop.

I've had these for two years and never really tested them, just used one to maintain my car battery once in a while. I assumed they would just keep the battery charged and not really charge one. However I recently used them together to charge a weak motorcycle battery in a couple days. It wouldn't crank before and then could handle multiple starting attempts with power to spare. Today under a clear sky and mid-day sun, one panel put out 1.84 watts, and the other 2.24 watts. I had expected them to come under specifications, so it was nice they exceeded the advertised rating. I didn't even aim them, just propped them on the bricks I've been using to tilt them. These newer panels seem to be much better at catching light off angle than panels used to be. My 7 or 8 year old AA battery charger really needs to lined up or power drops a lot, plus it never got close to rated power. The blue leds on these are helpful in saying there is current. They start blinking even inside and dark environments. However, I'm not sure the newer ones have this as the 5 watt panel I just bought does not and I've seen comments that these smaller panels no longer have them. That's disappointing as it was nice to know there wasn't some broken wire or other problem.

I used these two to try and maintain the engine and coach batteries in my RV. The panels drained both sets of batteries, so that I had to jump start the RV. Perhaps they work for places with lots of sunlight, but not for me. It is because these do not have a charge controller to prevent discharging during the night or other low light conditions. You can see this by the blue LED "charging indicator" flashing all night long. Plus, if you do have lots of sunlight, this device has no overcharging protection, making it easy to cook your batteries. So, a real system has to include a charge controller, like this: [...]