5 PCS LANTIAN 4 In 1 2.1A 4.2V Déchargeur de charge DC-DC Boost Converter 3.7V à 5V UPS RC PDB Board
Great boards for controlling IOT equipment such as ESP32... 5v buck boost stable with little ripple, doesn't overheat either. great little PCB.
This is a really useful board for low power IOT / battery management. Intelligently handles 1S lipo with low-volt cut out. Great power button feature too. And provides a stable 5V output for running embedded electronics. Great product, if a tad expensive.