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 Chuck Derrick

Yes! It works as a 3.7V DC to 5V DC boost converter and under ideal conditions also charges 3.7V Li-Ion batteries with a capacity of around 700mAh. The battery undervoltage cutout appears to be 3.2 VDC before the 5 VDC output stops boosting. The only caveat is that the load must be drawing at least 60mAh at all times for the boost converter to keep working. This can be a problem for low power applications. This is one of the main limitations of this design. Under actual load conditions, the conversion factor appears to be 85%. It outputs 5.1 VDC at a maximum load of 700-800 mAh and shuts down. There is only one RED LED on the board. There is no blue LED, RED indicates ON status (solid) and will flash while charging and when charging is complete it will become solid REDA as other reviewers have stated that it is based on "HOTCHIP HT4928S". It's funny that they named the chip that way because it gets very hot during operation, especially when charging 18650 3.7V Li-Ion batteries and under high-load conditions during the DC-to-DC conversion process. The metal fins of the USB port are partly used as heat sinks. This is a tiny standalone device suitable for various projects, while not perfect it still works. For the price you pay you really can't complain about the four star product rating!