The RV community is well aware that solar panels on the roof of their RV will allow them to recharge their batteries easily during the day. We believe that our 9 x 4 cell, monocrystalline is the right solution for most RVers. Since then, I have become solar-educated and solar-experienced. Before you can make an informed decision on what solar panel is right for you lets get a little background in how solar panels charge your 12 volt battery.
While the engine is running, the 12 volt battery is charged by the engines alternator. When the solar panels see daylight, the 12 volt battery is charged via the solar panels, through the charge controller to the battery. Ones 12 volt power is available throughout the RV.Via the 12 VDC to 110 VDC inverter, 110 VAC is available. If you dont already have solar panels, you are not likely to have a charge controller. If you were on a desert island, and had to charge your 12 volt battery, you could connect solar panels directly to the battery. Among other features, you would lose the ability to prevent battery overcharge. The charge controller allows you to top off your battery with energy while preventing overcharging (which shortens its service life). I can easily find 100 different, but equivalent charge controllers on the market. What is more difficult to find are good choices for solar panels. You may have found this listing based on searching 12 volt solar panel.
You need a solar panel that produces a voltage in the input rage of your charge controller (not actually 12 volts). For example, a charge controllers voltage input range may be 16 to 50 volts. Notice that the output voltage of the solar panel must be above the 12.4 volts required to charge a 12 V lead-acid battery.
A really good system uses one 18 volt or two 18 volt solar panels in series to supply an charge controller that in turn charges a 12 volt battery. There are all sorts of solar panels out there, but the best panel is made from 6 inch squares of monocrystalline silicon and had 5 buss bars. 36 of these cells are adhered to a sheet of tempered glass and framed with aluminum. A 6 x 6 silicon cell produces about 5 watts of power at 0.5 volts.A panel of 18 of these makes about 180 W and 18 volts. Our panel panels each produce 190 W in direct sunlight. Thus are higher performing than you will typically find. The more watts, the better. The second thing you want to look at is the voltage. You need one or two (more is OK) 18 volt panels. Note that these 18 volt panels may be called 12 volt but they will have voltage several volts above 12V in order to charge the battery.
The charging voltage has to be 2+ volts above battery voltage to successfully charge. I believe that our panels are the best deal going.This is a great value. May I use these panels for my off grid cabin? This is why in 98% of cases, a charge controller has 6 terminals. Two for the solar panels. The load is often a 12 VDC to 110 VAC inverter. Charge controllers come in 12, 24, and 48 volt varieties. For example, my personal off-grid system is a 24 volt system with which I directly power a 24 volt refrigerator. Typical 6 Terminal Charge Controller. These panels are the same high quality technology that has become standard on home installations. (not polycrystalline or another low efficiency technology) Full Size, 156 mm (6 inch) square cells. (not smaller cells producing less power) Includes 2 shading diodes per panel (not cheaper quality that eliminate the shading diodes) 5 buss bar technology (not the less efficient 3 buss bar designs).
What you want on your RV roof (or any placement) is the most power per dollar of solar panels. We think you cant do better.Are these 12 volt panels? Do I need one or two panels?
A typical charge controller might have an input voltage range from 16 to 50 volts. Thus one 18 volt panel or two 18 volt panels in series (36 volts) will both work well. Of course, the more power, the better. Will these panels work on my grid-tied system at home?
Lets assume that you are using a microinverter-based system. Microinverters are designed to work with 60 cell or 72 cell panels. Two 36 cell panels in series are electrically equivalent to a 72 cell panel. It would be difficult to find a 72 cell panel that outputs as much as our 380 W.
On my house I have microinverters connected to pairs of 36 cell panels. The item "Two Solar Panels 200 Watt Each, 36 Cell, Monocrystalline RV 12 Volt Off-Grid" is in sale since Sunday, June 9, 2019. This item is in the category "Home & Garden\Home Improvement\Electrical Supplies\Alternative Energy Supplies\Solar Power Supplies\Solar Panels & Kits".
The seller is "1ststepsolar" and is located in Dearborn, Michigan. This item can be shipped to United States.