I measured with different multimeters.
my 2 Sonoff POW R2 and my Sonoff Pow
vary a bit, the pow by 1 w difference
the Sonoff Pow R2 at AC voltage is 2 volts less than actual.
Watts and amps also give way and show a difference.
it would be good if you could adjust the values yourself!
I'm working on modification to use the sonoff pow to monitor the energy parameters over the limits of 15A .
Take it calm....breath.... I will not put more than 15A over the sonoff, I'm using a current transformer (60-5) so never will flow more than 5A over the sonoff. Like as is usually done in instrumentation.
The hardware modification is very simple but i'm only need to correct the current value that the sonoff is reading (because its afected by the transformation relation of the current transformer).
So like the partner, I need too add a constant to correct the reading values of current and voltage in ewealink.