Get one of these for your workbench (but as @philippejadin says, make sure to put it in a nice enclosure):
or cheaper/safer, one of these and power it from a USB battery pack:
(the second is only 2 W but that’s enough for many modules. There are more powerful options as well, e.g. Recom does 6 W converters in the same absurdly tiny form factor, but TME didn’t have them in stock. There’s also larger form factors with a bit more power.)
EDIT: Turns out the 2W I linked to is a “Medical Grade Unregulated Converter” which is maybe not the right thing 
Will take another look at what they have when I find the time.