Customer Reviews:
Showing reviews 6-10 of 29
 good to tinker with September 24, 2008
Josh Wakefield (Double Springs, AL)
5 out of 5 found this review helpful
I bought one of these kits from Amazon.com. One of the panels was broken in the first shipment. Amazon had UPS pick everything up and sent me another kit. Everything was in good order in the second shipment.
I went to my local Wal-Mart and bought two EverStart Marine 27DC-6 deep cycle batteries (115 amp hours each - $143.62 total with tax) to use with this kit. I also purchased four heavy duty battery terminals for #2/0 wire ($12.82). I went to Home Depot and bought two 2ft strips of #2/0 wire ($14.17). I connected the batteries in parallel with the #2/0 wire.
In theory, this gives me 230 amp hours of storage. I mounted the panels onto the PVC pipe and put it on the roof of my house. The panels are facing East at an estimated 30 degree angle. I chose this location because you can't see the panels from the road (minimizing chance of theft).
However, the general guidelines are: solar panels should face South in the Northern Hemisphere and North in the Southern Hemisphere; A solar panel's angle should be set to the equivalent of your your latitude plus 15 degrees during winter, or minus 15 degrees in summer.
After installing the kit and hooking it up to my batteries, I left it alone for about one week. This gave it time to fully charge the batteries. Today (9-24-2008 -- sunny) I tested the output with a digital multimeter at 12:08pm CST. I am located in Tuscaloosa, Alabama. The charge controller output voltage was 14.19 volts; and the amps measured 2.61.
In order to measure the amps, move the red wire on the multimeter to the 10A DC plug. Turn the multimeter knob to 10A. The multimeter needs to be in between the battery and the charge controller. Imagine a Mom holding a child's hand and a Dad holding the other child's hand. The child is the multimeter. The Dad is the positive battery termial. The Mom is the red wire coming out of the charge controller and going to the battery.
Watts = Volts x Amps. So, the charge controller was outputting about 37 Watts. In order to maximize my batteries' life, I do not want the percentage of charge to ever drop below 80%. This is equivalent to a 12.46 volt meter reading with my digital multimeter. I got this kit to tinker with. This is my first solar kit. Right now I have the included 200-watt inverter hooked up to the batteries. It is providing AC power to my fish tank water filter. I am going to add more devices to the inverter each week until I start getting close to the 80% battery charge. I recommend buying a device called Kill-A-Watt by p3international (about $20). It will show you all of an AC device's power comsumption information.
 Somewhat satisfied September 18, 2008
S. Garrison (Mesa, Arizona)
3 out of 3 found this review helpful
The panels are great. I received a sunforce 200 watt inverter, which quit working after 2 weeks. After 3 weeks, the charge controller quit working. I bought a new 1000 watt inverter and a new 10 amp controller and now things are good.
 Using for backup power in Florida August 31, 2008
J. D. Rosow (South Florida)
5 out of 5 found this review helpful
My husband and I don't like the noise of generators....nor do we want to store gasoline....With all of the hurricanes that blow thru here every year....as well as the FPL power outages that occur (even during regular storms)....we decided to put together a simple battery backup system to power a few items....This solar panel setup along with a few batteries does the job well....
The one thing we would like to change is the design of the two legs....We would prefer that they fold under the panels for storage purposes....They do not do that....They are fixed....
Studies suggest these panels may dissapoint August 27, 2008
M. Anderson (Silverdale, WA United States)
31 out of 44 found this review helpful
Shenzhen Topray Solar Co. Ltd. claims that, "The worldwide retailers, Wal-mart, HomeDepot, K-mart, Sunforce look to Shenzhen Topray Solar Co. Ltd. for Solar Products." It's a pretty fair bet that these Sunforce panels are manufactured by Shenzhen Topray, as are similar amorphous 15W panels marketed by Harbor Freight, Northern Tool, Brunton, and others, though Shenzhen Topray doesn't always label their products so some deduction is necessary.
So what does it matter who manufactures these panels? Because Shenzhen Topray has an almost singular reputation for manufacturing panels that are less than their rated capacity and are prone to failure. In a 2005 study by Arne Jacobson at Humbolt University of amporphous silicon solar panels sold in Kenya, all five brands of panels dropped from their nominal power ratings after a few months of exposure to sun, but the Shenzhen Topray panels lost 57-61% capacity whereas the others lost only about 15% capacity. After six months of study, the only manufacturer who had panels fail entirely (max power below 1 watt) was Shenzhen Topray, at a failure rate of 50%.
This is not the only study indicating Shenzhen Topray panels may not meet consumer expectations. A 2005 certification by Bodycote Materials Testing Lab of a different Shenzhen Topray amorphous solar product (that seems to no longer be in production) showed a Pmax of 10.2 watts rather than the nominal 15 watts. A 2004 Loughborough University study of four brands of panels sold in Kenya resulted in such outrage against the Shenzhen Topray products that a law was passed requiring testing before the importing of panels, and as a result very few Topray Solar products have found their way to Kenya according to Sass Peress in August 2006.
That was then, this is now. I read the more positive reviews here of this Sunforce product and hope things have changed. But the design of the very similar (if not identical) Harbor Freight 15W panels hasn't shown any obvious changes in the three years I've been aware of them, and in the three years following the publication of the first studies very little was done to improve their products to address concerns over capacity and longevity (again according to Sass Peress). I recently found a sale on the Harbor Freight 15W panels and bought a kit containing three of them, but I'll be taking them back even without testing them. I don't want to experiment with these for a year or two when known reliable panels are really not that much more expensive. Polycrystalline and monocrystalline panels by major manufacturers are typically warrantied to 80% of their rated power in 25 years. What do you suppose the chance is that these Sunforce panels will last that long?
I have not purchased this product, but have only read about others who have used similar products. So if you can prove me wrong with your real-world data of Sunforce PV arrays withstanding seasons of rain and sun and still putting out the rated watts, please do!
60W Sunforce Solar System August 26, 2008
Bernard S. Brownson (Denver CO)
2 out of 2 found this review helpful
I received the system quickly. It was easy to install with all the cables and necessary hardware. During peak sun days the panels put out 4.5 watts. This is enough for the lights that I am using.
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