Hi all,
Iām looking for a reliable smart plug with current/energy monitoring that meets these requirements:
- Ideally <1s time resolution (I need fast updates, not just averaged every few seconds.)
- WiāFi connectivity preferred, with MQTT client support out of the box (similar to how Shelly devices can publish to a local MQTT server when the load current changes. Iād rather not have to poll a deviceās HTTP endpoint a few times per second.)
- Provisioning/config: Bluetooth for setup would be a big bonus (I think the Shelly Plug S Gen3 can do this, too.)
- Reliability/manufacturer: Needs to be from a wellāsupported brand or at least something thatās proven stable and not a ācheap noānameā option.
Iāve been testing a few devices already. Most average power consumption over longer periods, while e.g. newer Shelly devices come frustratingly close to being exactly what I need.
Does anything on the market provide subāsecond resolution for current measurement? Most consumer plugs Iāve tried either average readings or only publish once every few seconds, which isnāt quite enough for my use case (measuring transient behavior and categorising operating modes of certain appliances).
Has anyone come across a plug that ticks these boxes? Or maybe a hidden configuration with Shelly devices that Iāve missed?
Thanks a lot for any help!
Edit: What Iām actually looking for is a fast response time to significant changes in power consumption (by more than a set amount or a percentage), so a high sample rate within the plug. A constant delay until the message is sent out wouldnāt be a problem at all.
The goal is to measure precise on-time for certain kitchen appliances, and to be able to differentiate operating modes (e.g. standby vs. operating, potentially power setting when on.)
Itās not exactly that, but letās say youād like to measure exactly how long a mixing device is mixing something, and you could guess the speed setting with some confidence.
It actually isnāt so much about receiving the data as fast as possible, but about precision in timing, which the plugs Iāve tested so far donāt really offer. Best I have seen so far is ~2s delay with a standard deviation of up to another second on a Shelly AZā¦ Not good enough. The investigation continues.
@tofubl
I use smart plugs frm EVE and ONVIS and both show the behavior you describe.
On the other hand I have several Shelly EM respectively PM and those reliability report any change virtually immediately.
In my RV I even use a Pro4 PM to manage the 10Amp breaker: Electrical heating draws roughly 8 Amps so when the toaster or coffee maker are switched on the breaker would fire after a few secs. ->
Hm, is it possible that āvirtually immediatelyā means different things to us? I have now thoroughly benchmarked a Shelly AZ and am currently investigating a Shelly PlusPlug S (Gen2 I think), and they are both far from where I would like them to be.
Hereās the result from a 1.5h run, toggling the load every few seconds:
The PlusPlugS V2 is even worse.
The real problem with this, other than delayed and missed events, is the standard deviation. A constant delay would be okay.
@tofubl
These are all smartplugs and I confirm that behavior with those i have, they are great for energy metering but not real time power monitoring .
The Shellys I use are those: https://www.shelly.com/products/shelly-pro-4pm
Ah, I see. I thought EM and PM are just other smart plug models. Sadly, not a viable solution for me- I need it to be a smart plug type of device. I wonder if those have more precise or faster measuring circuitry or if itās just a different firmware for a different use case.
@tofubl
But Home Assistant reliably switches heating off if too much power is drained and back on as soon as it is safe again. It even mirrors the coffee maker reheating when a coffee has been poured.