Review on MT3608 Boost Converter - Micro USB DC 2V-24V to 5V-28V 2A, Voltage Regulator, Power Supply Step Up Module 3.3V 5V 6V 9V 12V to 5V 6V 9V 12V 24V (Pack of 4) by Dale Toth

Poor design. The MT3608 is prone to catastrophic failure. I recommend using input fuses if the power supply is rated for high currents. I had one unit - MT3608 literally exploded and caught fire when it failed. Three more blocks failed. The IC in this design is very unreliable. I took two dead units and reworked them. Replaced MT3608 with Microchip's (from Digikey) MIC2250. The 22 µH inductor was replaced with a 10 µH coil. replaced the Schottky diode with a 1N4148 silicon diode - more efficient at higher output voltages. Substituted feedback resistors to change the voltage range - 1.24 - 13.6V one block, 1.24 - 20.9V another block. MIC 2250 seems to be more reliable. Also, where used, they are current-limited input sources. I strongly recommend NOT using them with high wattage, high current input sources. They can explode and catch fire. Use input fuses for high power sources. I absolutely cannot recommend this device. Bad design is likely to fail. Every order has failed completely. The photo shows one of the upgraded units with the MIC2250 chip. its pinout is pretty close to that of the MT3608 - only a jumper was added between pins 4 and 5 to match the 6-pin layout on the board. This board has two resistors (replacing the 2.4kΩ resistor) to get a 6.3kΩ value in the feedback loop.