I bought a step up converter on Amazon. It basically has the usual three pins, Vin, Vout and gnd. Vin is any voltage < 5V and Vout is supposed to be 5V.
I'm connecting a lipo battery to it, when I measure just the battery, I get the expected 3.7V. When I connect the battery to Vin, I get this:
Vin - gnd = 0.2V
Vout - gnd = 2.1V
I'd have expected to see:
Vin - gnd = 3.7V
Vout - gnd = 5.0V
I purchased 10 of these and I tried a couple, they all behave the same. Any ideas?
Here is the particular model: