Review on 4-Pack 18650 Battery Charger Protection Module, Power Bank PCB Module Board, Dual USB 5V 1A 2.1A with BMS Protection for DIY Phone Mobile Power Bank by Kim Maldonado

LATEST UPDATE: The seller contacted me and solved my problems by replacing the product. While the problems persist, they may still be useful to me on other future projects. My updated review relates to the customer service provided. UPDATE: Here we are a few days later and they were making a LOUD screech. Maybe cheap/bad caps? Almost done with it. Looks like they're on my return list :/ORIGINAL: So far these are "normal" modules. I've only lightly tested 2 so far, and one has started causing parasitic drain as the backlight stays dimly lit when off. They also have bad voltage drop, up to 4.4 volts but never around 2 amps. I wonder if they will be useful to me now.