yarachel25Pairs / 50PCS Solar Connectors - Male & Female IP67 Waterproof Connector (25 Pairs Solar connectors)

I clean the solar panels every 2 weeks on this season of the year (due to the dust on the air).The tie grid inverter used to produce 700 watts at 12pm-2pm, but suddenly it decreased to 500 watts and a lot of variation, from 350 to 500 watts in one minute. I was thinking about the cleanness of the solar panels.I cleaned the solar panels and the power did not increase as expected. I started checking the solar panels with a watt meter, but when I wanted to unplug the first solar panel (from the 3 ones that are in service, Canadian solar, 365 watts each one), I saw the plug on a poor condition. The connection was hot while holding on my hand (negative side).When I checked the positive side, it was cold, but the negative side was hot.When I tried to unplug from the 3-to-one connection, the assembly was burnt, overheated and it was not possible to remove one section from the other. I had to remove both sections and replace new parts. I placed some soldering on the cable-terminal junction after crimping.This did not solve the issue at all, the inverter continue producing 400-500 watts and the power fluctuation continued. When I check the connection after the breaker, where another MC4 connector were placed, the MC4 junction was damaged too due to overheat. I had to cut the section of the wire, place other MC4 connectors and weld them after crimping.I mean, 2-MC4 connectors failed on the same negative wiring after 2 working weeks. One was outside of the house, and the second inside of the house.

Summary: When it comes to PV, from an engineering perspective, your system is only going to be as efficient as the lowest costing bottle neck. For electrical interconnections, the single weakest link is going to be connectors, so buying a quality offering, is investing in the future efficiency of your ENTIRE PV system.Recommendations: You can use a digital multimeter (DMM) to check your connections after crimping them. As designed, once you screw on the one-way ratcheting cap, you will not be able to disassemble them without breaking the tab, so it might be a good idea to do the electrical check first. On a related note, the metal spanner wrenches by IGREELY below are much better for the disassembly.Pros: Good fit & finish.Cons: YARACHAEL does not appear to be a dedicated solar company. Conclusion: At $22 for 25 pairs (less than $1/pair); rating this 4-stars (non-specialty). Shop around, and buy in bulk.Related Products:BougeRV 44PCS Solar Connector with Spanners 22Pairs ~ $21 ($0.96/set)yarachel Solar Connectors - Male & Female IP67 Waterproof Connector (50 Pairs, Solar connectors) ~ $36 ($0.70/set)https://www.amazon.com/gp/product/dp/B08DQQ4CJ6iGreely 4 Pcs Solar Metal Spanner Wrench ~ $11https://www.amazon.com/gp/product/B08J82G9J9

Happy with them. The connectors and pins are great, nice quality.I found that once I pressed the pins into the connector, it was easier to screw the grip part on if I pressed the rubber gromet into the connector as far as possible before assembly, if you don't the grip cap can jump threads an start to strip.side note: I purchased the Renogy assembly tool from Amazon and it does not fit these connectors.The Renogy tool is too large for the grip end of the connector. The tools does fit the male/female ends, so you can hold that end with the tool and then use pliers to tighten the grip side. The Renogy tool also works for disconnecting the MC4 plugs after they are connected. It has a pair of pins that clip on the connector so you can pull them apart.I also purchased the crimp tool for the connectors from Amazon, and that also is a quality piece for $16. I used the middle 5mm? crimp area on the crimp tool. It provided a nice crimp. Hope this helps.

I buy these by 4 boxes at a time. At my normal distributor I can only get 4 for the price amazon sells 20 for. Ive been using them for around 3 years and a couple hundred installs and not one failure. I would highly recommend .

I make my own solar panel cables, and need these MC4 connectors often. They have a great fit, and make a solid performing connection. They are weatherproof, snap snugly for a positive hold and will not come apart.This is a complete set of 25 pairs for both the female and male ends, including the metal core connectors for both. They crimp cleanly and make a long lasting and solid connection. These are quality MC4 connectors that will perform up to 30A DC current, and I highly recommend them. They get 5 stars from me.