You might remember this small module from the previous InTheMail, this is the Ruideng dc-dc converter with a claimed efficiency of 95%. Now a figure of 95% efficiency is not unheard of these days, many dc-dc converters can achieve this with proper circuit design.
This particular model uses the MP2307 converter chip manufactured by Monolithic Power and if we take a look at their datasheet we can immediately see where they got the 95% efficiency figure they advertise.
If you own fancy equipment like a source/measure unit than one instrument can do all the measurements and data log the results as well but a source/measure is out of our budget so we will be using multimeters for this test.
Here are links where you can find the equipment used in this video: