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

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.

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.

We recently had hurricanes in Florida lucky not much happen where live except the neighbors lost power because our retention pond flooded the road and up our front lawns it flooded theirs on the ground transformer but it didn't flood our on the ground transformer so we didn't lose power.I was lucky but made me think about next season and the fact my wife is recovering from a stroke in bedridden until she gets back use of right side at least her mind ok, slow recovery.But in the past, we been days without power and once 12 days without power but had lots of sun after storm passes.So getting some panels and a Solar power station (EcoFlow Delta 2 Max $950 on sale) that I can run some stuff for her like the TV and Fans and adjustable bed and a few mini fridges until power comes back online.I order first set and got them working with the power station, the power station can take 2 solar inputs so order another 2 set of these.The power station input is 11-60 volt and 15amp max so I can put 2 panel in series with 44 volts 5.5 amp max and then put 2 set of series in parallel for 44 volts 11 amps max I was getting real world 338 watts input to the power station so that like 84% of 400watts rated in full sunlight not bad at all.I only need 1 more set but I bought another smaller power station that only has one solar input because the DEAL on it was too good to pass a 1024ah 1800w output EcoFlow Delta 2 black Friday for $399.So now I have 1200 watts max but really real word more like 1000+ to change my two power stations.1 set of 4 $199, the next 2 sets of 4 $189.They are very well made and sturdy and are package really well, I only had to file down a few spots at the corners that had little sharp edge to it other than that Great Panels.

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