It is probably not the best way to get reliable power modules, but we currently buy cheap ones from the local RC shops or Banggood or Ali Express and throw them away if they don't work as expected.
However, I have found several that work perfectly, with stable power to the flight controller and accurate battery voltage readings, but with bad current sensor readings.
A sample log is here:
I use a big BAT_A_PER_V to amplify the noise. The flight controller gets a stable input, and the battery voltage measurement is accurate within 1%, but the current measurement is 0 with a bit of noise.
The module is this one:
Has anyone tried this PM? Is there a hack to get valid current readings from it?