Power measurement differences after ESPHome updates

ESPHome
1

Hello guys!

I’m using several Athom Smart Plugs V2 to measure the power consumtion for all kind of things. These plugs are integrated into Home Assistant. So far everything works. Now by the end of May I’ve noticed that the power consumtion of my server changed. Since the server runs 24/7 and the power consumtion does not vary that much, it was very weird to me that there was such a change. I thought okay, maybe some updates on the server led to higher power consumtion. Then four days ago, on the 22th of July, the same thing happened again and the power consumtion went down again like it was before the increase in May. I’ve checked all the logs on the server and HA, then I realized that I’ve installed an ESPHome update for HA and all of my Athom Smart Plugs on that exact same day, the 22th of July.

Screenshot 2024-07-26 151136
Screenshot 2024-07-26 1511361321×442 22.3 KB

You can clearly see the increase and decrease (back to as it was before). So my question is, can this be related to the firmware update?

Kind Regards

2

Yes it can. Calibration, filtering and other things can all happen directly on the device :raised_hands:

Did you change the yaml? Can you post it (both if it changed)? :page_facing_up:

Also the previous version would be interesting or mandatory in case the yaml was the same :bulb:

3

Thank you for your response. Oh interesting! I haven’t changed anything in the yaml, except for adding

ota:
  platform: esphome

a while back. The package url within the yaml is

packages:
  Athom_Technology.Smart_Plug_V2: github://athom-tech/athom-configs/athom-smart-plug-v2.yaml

The rest of the yaml is just the default one.

4

What I’ve just noticed is that the plug reads:

Voltage: 235V
Current: 0.82A

To my knowledge it’s

P = U x I

That would be 192.7W instead of the sensor reading from the plug which reports around 130W…

5

Only when the power factor is exactly :one:

Maybe that’s what you are after? In April your device got “Apparent Power” and “Power Factor” additions in the yaml :point_down:

1 Like
6

I see, that explains the change. Could you please explain a bit what exactly these two things (apparent_power and power_factor) are?
I always thought that these plugs are quite accurate on 10W+

7

You know not what you ask. I have a Master’s in Mechanical Engineering, and even after my minimal Electrical Engineering courses (and working in Energy Efficiency my entire career), AC power still feels a bit like black magic to me.

1 Like
8

Thank you. It’s just weird to me that with my power meter the measured power is quite a bit higher. If I take the example of my server in my initial post, where the plug does measure about 125-130W, the power meter does measure around 185-190W, which is a huge difference, especially when considering that I’m using 6 of these plugs to measure to consumption to calculate the energy costs.

9

Update!

plug_restart
plug_restart1292×437 34.5 KB

I’ve noticed that when I restart the smart plug via HA or ESPHome, the power usage is quite a bit higher. Not nearly as high as it should be, but still. The strange thing is that this holds for about for 6 hours! After that time, the power usage goes back down again. As you can see in the screenshot I’ve restarted the smart plug three times and the behaviour was always the same.
I’ve also flasehed Tasmota on one of the plugs to check against the ESPHome firmware and my power meter, surprisingly with the Tasmota firmware the readings are very accurate and +/- 8W identical to my power meter.

So the two questions now are:

  • What is this higher reading for 6 hours after a restart of the smart plug?
  • Why does the ESPHome FW differ compared to Tasmota?

I really love ESPHome and want to keep it on all of my devices if possible, but if this isn’t fixable, I have to switch them to Tasmota sadly :frowning:

10

Could someone please help me understand what’s going on?