Review on 🔌 Onyehn 10Pcs 5V Boost Step Up Power Supply Module with Lithium Battery Charge Protection Board - HOTCHIP HT4928S DIY Charger with LED Display, USB and Micro Port (10 Pack) by Oscar Chambers

First off, this review is all about the Onyehn 5Pcs 5V Boost Step Up. The main difference from the product description is the presence of a CHIP on the board, it's not 134N3P, but HOTCHIP HT4928S. And there is no blue LED on the board, so don't chase it. The RED LED is marked as LED 2 on the circuit board and the positions of LED 1, LED 3 and LED 4 on the circuit board are free. Pin 2 of the HT4928S connects to LED 2, blinks to charge and stays on to complete charging. Pin 1 of the HT4928S is connected to free + LED 1, but goes HIGH when pin 2 to LED 2 is off. It would be handy to tell when the V output is on, but alas, MIA. I am including a diagram and front and back photos for reference. I can't find a description of the internal structure of the chip in English, maybe someone else will. The HOTCHIP charges better than any of my TP4056s and shuts down when fully charged at 4.26V. The chip heats up warmer than the rest, and even the standard-size USB connector is used as a heatsink. When the device turns off, VOUT on both USB ports goes 5.19V for about two seconds, then turns off when you have no load. With a load of 1A with no load, the boost holds 5.1V. At 2A, the voltage is cut off. I did not check for undervoltage at the battery disconnect point. This is a great ultra small device that really works.