3 Responses to “Sunforce 39126 246-Watt High-Efficiency Polycrystalline Solar Power Kit”

1. Ollie says:

   August 1, 2008 at 12:04 pm

   Review by Ollie for Sunforce 39126 246-Watt High-Efficiency Polycrystalline Solar Power Kit
   Rating:
   Rather than pulling out a generator and electric cord for daily charging of my RV batteries I decided to purchase this set and hoped it would supply all my electrical needs while camping. It does, very well. I took the advice of another poster and purchased a more efficient charge controller separately, the Morningstar MPPT and it’s display panel. The MPPT controller increases the charging efficiency by up to 30% or more. These solar panels now easily keep all 4 of my trailer batteries charged and recently averaged at least 10 amps of charge for each daylight hour. I searched all over the web and Amazon had the best price on this particular set, or anything like it. The money saved is enough to upgrade the controller for more efficient charging. The set came with nice extras like a 200w inverter, voltage test gauge, plenty of wire and 6 mounting brackets per panel.
2. F. Templeton says:

   August 1, 2008 at 1:01 pm

   Review by F. Templeton for Sunforce 39126 246-Watt High-Efficiency Polycrystalline Solar Power Kit
   Rating:
   The panels were shipped to me on the west coast from the east coast and arrived in good shape, the outside box was tattered but the inside boxes were fine.

   Was disappointed that the controller, battery tester, modified sine wave inverter, wire, brackets, and bolts were all loose inside the box with one of the panels; looked like they could easily damage the panel’s white backing.

   Connecting the wires with lugs attached for the first panel to the controller was easy. When I tried to connect the second panel to the first one I found the provided screws too short to allow for a lug on the end of the wire. I had to cut off the lugs and flatten the wire before the screws would engage. I’m sure it’s fine but it’s not as secure this way.

   GOOD POINT: On day two with only one panel in service I had a reading of 7.2 amps compared to max rating of 7.14. That only lasted for a couple of minutes, I usually avereged above 6 amps on sunny cool days except early morning and late evening. When cloudy I had power reading anywhere from 1 amp to 3 amps.

   BAD POINT: Of the 108 rectangular cells, I only had to shade a couple of them for the output to be reduced to near nothing. Don’t install the panels near a flag pole or mast, just the smallest amount of shade will make them useless.

   I watched the 4 minute video on Amazon that showed the panels being setup in a field. From that idea I’ve designed a teeter totter frame to mount on the roof peak that does not have a southern exposure. It teeters east in the morning and totters west in the evening with about a 48 degree range and a 8 degree tilt to the south. From what I’ve read elsewhere this gives me 20% to 40% increase in output during the summertime when I need it the most.
3. HMMWV says:

   August 1, 2008 at 2:00 pm

   Review by HMMWV for Sunforce 39126 246-Watt High-Efficiency Polycrystalline Solar Power Kit
   Rating:
   This kit is two good sharp panels (123W ea) for 246W total. Their power curves are ideal for 12V battery charging (or 24V if wired in series for 24V systems) I evaluated the sharp 123W panel 2 years ago and found it to be well made, but then sharp scrapped it and introduced the 130UJF with higher efficiency. Note these are polycrystaline vs. other sunforce (larger area) monocrystaline panels which only put out about 15W in this size.

   Sharp discontinued the 123W version in 2008 due to efficiency improvements (this model is about 12.5%) and replaced it with a 130W panel in the same form factor running 13.1% efficiency. This package deal will probably go away when stocks of the ND-L3EJEA panel run out since it has been discontinued by Sharp. That’s no big deal, but later if you want to add to it you find an engineering problem. Your original panels are 123W and your newest match is 130W, hence no “good” match for series wired installations unless you want to exactly double your capacity with a second string of panels. You will also find that paralleling the new 130W with your 123W will alter the power point of the combination. You might check around for the newer 130W (sharp p/n ND-130UJF) now and compare $/w to just buy the panels.

   The inverter most likely will not find alot of use - it’s value is near zero.
   
   The charge controller could get you more total watt hours per day if it were a MPPT design, but at the price it’s pretty much free. If they would re-kit this without the inverter and controller they could beat the $5/watt “low cost solar” pricepoint

   [The $5/watt pricepoint is a guideline you bump into laying out DIY systems under 1KW and is only an approximate rule of thumb. In general if you do it yourself you will end up around $5/watt for a system - if you beat that by alot e.g. $4.25/W you deserve a pat on the back. Over $5/watt and there may be better deals waiting for you - but you may have to buy more panels to get the pricing. This $5/watt pricepoint surprisingly has not moved for years!]

   When you take delivery of these panels you can see the individual cells and the wiring between them you can see that the 130W and 123W panels are identical in design - just the cell efficiency changed.

   If you bought 2 of these kits now you would have the versitility to parallel all 4 for a 492W 12V system, or make a 2 series, 2 parallel 492W 24V system, or even a 4×1 panel series wired 48V 492W setup. Sell the inverters and charge controllers on ebay and buy a MPPT system with the revenue!