Hello, I’m new to domotics and Homey Pro. I have installed 8 smart plugs already, connected my wallbox, all robots (vacuum, lawnmower) etc. I’m quite happy but I’m really puzzled with the values of power and energy consumed by the devices plugged to the smart plugs. It’s complete non sense!
I could not believe for example that my router and 2 modems would consume the 123W power indicated by the plug so I have inserted another smart plug to the first one and got 73W on the second ! Quite a difference. I have tested a third one and I’ve got 100W! Voltage values reported at the same time by the 3 plugs varies from 234 to 241V !!!
Therefore, I have started testing separately all smart plugs with a good and reliable external wattmeter with an electric load I could choose and… I have identified that only 2 out of 8 smart plugs actually report the correct value! All the others are not well calibrated !
Of course, I know that there is a coefficient in Homey Pro that can be applied to the values reported by a plug but that means that as from now, I need to evaluate each plug with a stable electric load to calculate the coefficient to apply to power and energy in Homey Pro !!
ANOTHER VERY IMPORTANT INFO: the expensive smart plugs that you can buy on Amazon (~25€) are not more reliable than the cheap ones you can buy on Aliexpress (5€). This is the exact same crap that requires adjustment !
Homey Pro, like Home Assiatnt, Smartthings, etc., they are all good to automate but all bad to measure and monitor due to the smart plug being unreliable.
So basically, if you use unreliable smart plugs you get unreliable results 
My experience with Shelly and LIDL/Silvercrest plugs is that those seem to provide quite reliable data.
FW updated IKEA INSPELNING seems to be quite accurate as well. (not 100% but quite…)
Never had anything but correct information from my Aqara plugs. I know what the devices should be using and can confirm that through my plugs.
the expensive smart plugs that you can buy on Amazon (~25€) are not more reliable than the cheap ones you can buy on Aliexpress (5€)
Yes.. if you buy 25 euro smart plugs that are simply rebranded airdropped Aliexpress plugs then you indeed will not notice any difference.
Would be a good idea to say what exactly you are using as plugs because if 3 IoT software platforms are getting unreliable information from your stuff .. well.. im not gonna say I suspect your stuff, but I suspect your stuff 
Hello, my apologies, newbie’s mistake. After extensive testing with an external wattmetre. Here is the conclusion. Not all zigbee plugs behave the same in Homey Pro. E.g. NOUS smart plugs display by default the actual power consumed by multiplication of the current and the voltage. If you disable this calculation, it will display the power reported by the device without taking into account the power factor (or efficiency). Other plugs display this device power instead of displaying the actual power consumed. So the difference between values reported by two different brands of smart plugs is actually the cos phi !!! E.g one plug says 123W and the other says 73W, the cos phi is 0.6. The devices takes 73W to power up but it consumes 123W in reality.
I have 3 different brands of smart plugs and then I will have to check what is the default value reported for power (with or without the power factor).
Sorry if I have worried some people here.
Regards.
