Few months ago I made small portable power supply, in small plastic case I managed to pack a 2 pack of 18650 li-ion batteries, tp4056 + DW01 charging module, cheap chinese boost module, and a very common on ebay
module. On the side of the case are two rocker switches, one for power, second one for current limit selecting, and two cheap banana plug sockets. It's amazing that it worked when I made it (most of the times when I make something, they don't really work as intended, or at all). These cheap modules are a some way to make a simple power supply, as they show voltage and current, they not as accurate as other more expensive solutions but they quite handy at times. Some small modifications, and you're good to go (just replace pots for some easier to use ones).