ECO-WORTHY 400W Solar Panels 4pcs 100 Watt 18V Monocrystalline Solar Panel Module for Off Grid PV Power for Home, Camping, Boat, Shed Farm, RV,12V Battery,2-Pack 2 * 100W

Great set of panels, easy to install and easy to maintain. Size and weight ratio is good considering the quality of the panels. Output seems to be great so far.

In answer to the question of “why are my solar panels underperforming their rated capacity” I have some information that you might find useful. The rated capacity of these 4 panels is 400 watts. You probably already know that panel angle and whether the weather is sunny or cloudy can have a effect on power output. What you may not know is that how you connect your solar panels to the power station can also have a huge effect.My power station is rated at having 500 watts maximum solar input power so I assumed that I should have no problem connecting it to 400 watts of solar panels, but my power station has maximum solar input voltage of 60 volts and maximum solar input current of 15 amps. Each of the 4 solar panels has normal output voltage of not more than 12 volts but a peak output voltage of 19.5 volts and peak output current of 8.33 amps.If you connect the panels in parallel (positive of one panel to positive of the next panel and negative to negative of the next panel), the peak output voltage would stay at 19.5 volts but the peak output current would be 33.32 amps which exceeds the input current capacity of the power station. The power station would reject the current over 15 amps, so power output would be reduced by a little more than half and the excessive current could damage the power station. If you connect the panels together in series (positive of one panel to negative of the next panel), the peak output voltage of the 4 panels would be 78 volts and the peak output current would stay at 8.33 amps which exceeds the input voltage capacity of the power station. Power output would be reduced by about a quarter and you would again risk damage to the power station.In this example, I should be able to maximize power output by connecting the panels in series using a solar power controller. There are two types of solar power controllers, PWN and MPPT. PWN controllers are cheaper but they only reduce the voltage without a corresponding increase in the amperage so you lose power output. The MPPT controllers cost more but they increase amperage as they decrease voltage with no loss in power output. I have ordered an MPPT controller and am optimistic of getting optimal power production.

I picked up these 4 - 100w panels for about $50.00 each on a Black Friday deal, thinking they would make a nice addition to my Express van camper. They shipped quickly, but only 2 of the 4 arrived initially, the 2 went back, and the 4 finally arrived. I tested each panel, one at a time, connecting them to my Delta 2 while on my balcony. I was looking for consistent performance from each panel, and how they would perform, flat versus tilted, in So Cal on a sunny December day. The panels each delivered 20 - 30 watts flat, and about 35-45 watts tilted around 30 degrees. Performance was about what I expected and reinforced my plans to incorporate some kind of tilt mechanism when mounted on my vans roof.Then while fiddling with a panel, a gust of wind caught it, I lost my grip, and watched my panel crash to the ground, fortunately it hit on a corner and stuck into the sod. After rinsing it off, inspecting for damage, finding nothing visible, I tested it out again and was surprised to find it working just fine. These things are well built. It is now 2 months later, they are mounted on the roof of my van, with my homemade tilt mount mechanism, and the days are getting longer. The panels are mounted in a serial - parallel manner and I am happily getting as high as 300-315 watts on a good day. Overall, I am pleased with the purchase, performance, and the price. As spring approaches, I may get a few more watts yet, as I tinker with my tilt angles.

Please note that this product requires something called well nuts to connect it to campers, RVs or boats. Also note that well nuts do a terrible job in high winds. Mine blew off during high winds while coming up from Thatcher to Phoenix after an event. My suggestion is to bolt it down to a camper roof rack. I bought one and I bolted it fast to it and that is not coming off. Do not trust well nuts!Other than that, these things work perfectly. I bought this to mount my replacements on. Much sturdier.https://www.amazon.com/dp/B0896XJQN6?ref=ppx_pop_mob_ap_share

Deceptive advertising. These are not 100w panels as they only put out a max of 75w. I purchased 16 of these and unfortunately had already installed 8 of them before realizing that my control charger was only getting 300w per 4 panels, 600w total… in full sun. My other brand 100w panels (set of 4) was doing 400w. These are mounted 8 inches from the Eco-worthy panels capturing the same sun. The separate reading were from 2 BougeRV 30 Amp Chargers also sitting side by side on my power board and switching inputs between the chargers.