Beaster 5 Pcs DC-DC Boost Converter Module Voltage Adjustable Step-up Circuit Board Voltage Regulator DC 2-24V to 5V 9V 12V 24V 2A with Micro USB Input

Bought the 5 pack in spite of the bad reviews because they look identical to other listings that have good reviews. I only used one but that one worked perfectly from the beginning and has been on ~40 hours powering a 12v pc fan from a 5v power source. I did follow another listing’s instructions to turn the adjuster 15 times clockwise before powering it. It showed up at ~28v when I first measured before reducing it to 12. I can’t say whether the other 4 will work just as well because I only needed one.

Acidently ordered two orders. Out of ten; 4 seems to be DOA. 5th one worked and threw out the rest. Isn’t worth the stress headache and time to troubleshoot the next time I need one. I order five pac expecting one or two to fail but the first 4.. next!

As long as you stay below 5W or so these things are bombproof. Nothing in a SOT23 package is going to step an 18650 up to 12+ volts at more than half an amp or so.

Great and inexpensive boost modules. Used them for boosting DC voltage from a USB power bank (5v) to a PC cooling fan (12v).

Two of the five units released their magic smoke upon initial power up. Third survived long enough to set output level before it quit, but didn't try the remaining two units. Needed 600mA from a regulated 12VDC input. I doubt these would be suitable for any application...

Every single one of these failed on either the first power-up, or the second. The failure modes varied from bursting into flame to just silent lack of operation, but the number of units that would survive two applications of power was zero.