FWIW, my old Efest LUC V4 charger finally experienced a failure after years of use. The spring broke on the circuit board feeding the left hand bay. It still charges on bays 2, 3, and 4, but I broke down and ordered a new one from Ebay for $21.99. For that price it isn't worth cracking open and getting out the soldering iron. The case is glued together. Those springs are hooked into the circuit board and soldered in place, then hooked onto the slide. The other 3 bays have gotten similar use, so I can see 3 more opportunities for bay failure!
In my searches, I discovered that there are clones out there being sold as Efest charger products and buyers report that they fail pretty quickly. I found an Ebay seller that guarantees the product in the original sealed packaging with UPC code and warrants it to be an original Efest LUC V4 new 2018 version. Trusting soul that I am, I ordered from that seller. He advertises himself as an authorized Efest distributor and displays the charger in an Efest box.
Lots of products go out the back door into a van in Chinese factories during night shift, according to some articles I've read. They are supposed to be authentic, but the scan codes don't hold up if you have a warranty claim. That was rampant a few years ago with Nike clone sneakers made in the Nike factory and sold on the street by workers. We'll see if mine passes warranty verification when it arrives.