Why all Zigbee Smart Plugs are unable to measure low power consumption

Hardware
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1

Hello everyone,

I am looking for Zigbee smart plugs (EU plug) that can read low power consumption (we are talking about standby devices that can consume 5W or less or devices that when running consume 10W).

The models I have tried are as follows:

  • blitzwolf shp13
  • generic smart plug tuya recognized as TS011F_plug_1
  • nous A1Z

Connecting a device that consumes very little power, 5w, 3w, 1w I noticed that they all have the same problem: the power value reading is 0. It starts to give sensible values from 20W and up.

The current value seems to be detected, 0.01/0.02A in my example, however the power value always remains at zero.

I have read many threads here on the HA forum, but have not found any insights with respect to this issue of low power consumption.

As a counter-evidence I have a WiFi socket (TP-Link Tapo P100) that even gets to read 0.1W, so I remain incredulous that all Zigbee sockets are affected by the same kind of problem. Is it perhaps an inherent limitation of the technology
whereby it is not possible to have such low readings?

You can see here how Z2M recognize the 3 plugs:

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Following an image where I plugged in the same device, and you can see how the readings are provided:

Generic TS011F_plug_1 model:
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BlitzWolf SHP13
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NOUS A1Z
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And finally, a TP-Link Tapo P100, you can see the very low W value
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At this point I am a bit desperate, because despite several attempts none seem to provide the values as expected. I don’t want to keep spending money to buy different models and brands again and again in the assumption that I will find something that works

Does any of you have experience with this problem?

If indeed, there is no Zigbee smart plug in the world that can provide this kind of value, I will have to lean toward using the Wifi version

2 Likes
2

My Aqara power plug reads my PC when off (a couple of USB devices plugged in), and it never shows 0. Had the PC on today so the scaling is a bit off, but you can see the current power draw.

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3

Thank you @fleskefjes,
you actually save my day.

For the first time I’m using a Zigbee plug and I’m getting the actual value of the power:
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Unfortunately the cost of a single plug of this model is 2-3 times the average cost of all the other smart plug I tried. But I guess the quality comes with the price.

Do you know any e-shop where I can buy them in bulk? I only find this article on my local Amazon website, and unfortunately I did not find anything on AliExpress of chinese shops counterpart

4

Glad to hear I saved your day :slight_smile: Sorry I don’t know where to buy in bulk, I bought the plug locally here in Norway myself, and was about to suggest Aliexpress.

5

I own smart plugs from blitzwolf and nous but only wifi and not zigbee ones. I don’t use the manufacture *ware but esphome instead so I can fine tune everything and also get maximum accuracy (not limited to only have one measurement every 5/10 seconds) to get real world readings :muscle:

It all makes me think that the hardware should be able to achieve good/accurate readings but just the *ware on the plugs is of no (little) use regarding power readings :person_shrugging: