LM2596HV is a great buck converter capable of stepping down ~5-60v down to 2-60v.
Unfortunately there are many fake HV's.
I figured out (pretty sure) how to tell a fake LM2596HV from a real one. Feeling pretty smart about myself right now ;)
This vid is a good demo of the real vs fake but he doesnt have a method of confirming until you test it, but the differences Ive noted show up on the model that he tests as well.