How many is “a few” KP115s and HS300s ?
Currently three HS300 power strips (a strip counts as one device) and two KP-115 plugs. Well below what should be a limit as I read it.
Actually right at the limit - 3 x 6 plus 2 = 20 outlets… support@sense.com might be able to help to see if that is the issue.
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It shouldn’t be. The Sense documentation specifically states that the power strip (HS300) counts as one device regardless of the number of things plugged in.
The definition of the limit has changed recently to clarify HS300s. You still should be OK per the guidelines, but that’s a little network dependent too. Just trying to think through possible issues.
Is there a limit to the number of smart plugs I can connect to Sense?
The number of smart plugs is limited primarily by Wi-Fi network bandwidth. Typical Sense users can use about 20 smart plugs without issue. Note that each plug of the TP-Link HS300 smart strip counts as 1 smart plug, regardless of status.
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The level of strain the smart plugs put on a Wi-Fi network has been a curiosity of mine. My internet performance can be poor at times, but I have no idea if this is a problem with bandwidth on my local network or with my ISP (Cox). Have you seen anyone experiment with this or shown there to be an appreciable effect on how other devices (laptops, phones, etc.) perform?
This is interesting, as I always assumed the 20 plug limit was a hard limit set by Sense. Would setting up a secondary Wi-Fi network dedicated to smart home devices be a good way to both ensure the plugs don’t hinder Wi-Fi performance on other devices, and increase the max plug limit? Does this soft limit mean the max # of plugs is theoretically infinite if the network had enough bandwidth?
Regarding the potential bottlenecks… Is data from the plugs routed directly to the cloud, and then from the cloud to the Sense apps (Wi-Fi, router, and ISP bandwidth potential bottle necks)? Or does the plug data first have to be sent to the Sense unit in the utility panel (making the radio of the Sense unit another potential bottleneck)?
How does one know when they’ve maxed out the # of smart plugs they can use? i.e., when the Sense FAQ post mentions “Typical Sense users can use about 20 smart plugs without issue”, what are the issues one would expect to see? Degraded performance on all network devices, or just on how the plugs perform? In other words, is the amount of total bandwidth the smart plugs can consume capped or denoted as a low priority to prevent disturbing regular network usage?
I do not think a limitation is a result of a local WiFi network. My HS300 uses about 10MB per hour of local WiFi traffic; this also includes Home Assistant querying it. I have a handful of HS105s (which do not include power information, and are not included in the Sense app), and they only use about 1.25MB/h with Home Assistant status updates.
My guess is that the local Sense device itself only has so much CPU power to process plug status while retaining an acceptable level of performance for what it normally does.
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It sounds like your belief is that the power consumption data from the smart plugs is routed to the Sense device, not to a cloud server (managed by either Kasa or Sense). I assume the numbers you provided for local Wi-Fi traffic are for data transferred only between the smart plug and the router/AP. Do you happen to see Wi-Fi traffic between router and the Sense device that correlates to the traffic from the plugs (i.e., 10MB received from the plug results in a 10MB transmission to the Sense device shortly after)?
Do these data numbers give an accurate representation of the total demand the plugs placed on the Wi-Fi network, or does it omit the “behind the scenes” operations like handshaking that are required to transfer this 10MB of data? In other words, could these plug still be a significant strain on the Wi-Fi network even though the amount of actual data transferred is small. Your findings seem to contradict the statement of “The number of smart plugs is limited primarily by Wi-Fi network bandwidth” in the Sense FAQ shared by Kevin above. Once again, I’m a novice in networking so I apologize for any lack of understanding (not questioning your findings, just trying to better understand what they mean)(for reference, I’m a design EE but work mostly in the realm of physical hardware / Hi-Rel electronic packaging).
(Lower priority) Out of curiosity, do you see any change in the HS300’s data transmitted per hour vs # of outlets on strip utilized, how much power device(s) are using / how frequently measured power use is changing, whether you have the power meter for one of the devices open for the hour, etc.? Or does this 10MB remain fairly constant?
Do you have any HS110s or KP115s? It would be interesting to see if the data rate for a single plug is 1/6th the rate seen on an HS300 fully loaded with 6 devices plugged in.
You’re right, this is purely traffic to/from the AP. Based on the other devices on my network, though (e.g., Nest cameras putting out 1GB per day, each, to the internet), I don’t think local WiFi is the bottleneck for smart plugs, at least based on throughput alone. It’s possible some APs are unable to handle a large number of clients routinely transmitting data.
These numbers are coming from my UniFi AP. I’m not sure what layers of the network stack it’s including.
I haven’t looked into the HS300 data in that level of detail, yet. No HS110s or KP115s, either.
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A few additional thoughts.
- I agree that the main issue is Sense monitor processing power. The “too many plugs” failure mechanism I observed was the plugs dropping out, then the monitor itself dropping data from the main CTs until it eventually went offline from task overflow.
- Another possible issue might be peak traffic. The Sense monitor sends out a broadcast “emeter real-time” request on the local network every 2 seconds. All the appropriate listening Kasa devices answer back, all probably in a fairly tight timeframe, so there’s lots of Sense smartplug traffic during that fairly short period.
- I don’t think there is a difference if the HS300 plug is unused. The data is still sent back.
- There’s some code here that lets you play with pulling power data off a Kasa device. If you turn on the debug options you can actually see the messages being sent back by the smart plug.
Any resolution to this? My KP115 works with the KASA app but Sense no longer detects power consumption from it. I removed it from Sense and then integrated it again. Sense found it as a new device but doesn’t detect power being drawn from it, even though the KASA app does. One plug…
I’m trying to collect all the issues with Sense/Kasa here. The KP115 / KP125 have a known anomalous behavior that seems to break the integration, but only on some types of network gear. My big issue are HS110s that become network zombies. They become unpingable from some clients, stop talking to Sense, yet can work OK with the Kasa app. The ping issue tells me there is something more than just a problem with the integration.
Hello @jerry, @kevin1, and all,
I believe I have recently experienced the same or similar issue. I’ve had my Sense monitor, four HS300’s and four KP115’s working flawlessly for several months. I’ve even performed some initial testing of integrating sense and the plugs into Home Assistant running in a Docker container on a Synology DiskStation.
They are supported with a meshed pair of ASUS RT-AX88U’s and ~800+ MB/s broadband internet.
On May 2nd some scheduled maintenance was performed and this seems to also be the last date that I have any data from the Kasa plugs.
Rebooting the routers and updating their firmware, updating the Kasa firmwares, and power cycling the Sense monitor have not resolved the issue. These plugs still show in the app, however; the control buttons are greyed out with "“n/a”, and as mentioned no consumption or status is being detected and reported.
If anyone was any other ideas on what to try or what the cause might be I’d appreciate hearing about it.
Thanks everyone
@TechGuy, I wish I could give you a definitive view of what the problem was/is and an associated solution, but the TP-Link disconnection symptoms seem to vary based on type of networking gear plus are somewhat intermittent. A few thoughts:
- With 4 HS300s (24 outlets) you are slightly over the recommended limit (20) for the number of outlets that the Sense monitor can service. That can result in dropout issues from an overworked monitor.
- @ccook caught this behavior of some Kasa plugs every 5 days. That seemed to be the cause the disconnect problem for some users.
- Right now, my Kasa plugs have been reporting reliably for a few months. Things that I have done - updated Ubiquiti AP / switch / router firmware, fixed IP address leases for Kasa devices, regular pinging of Kasa devices.
Kinda off topic. But are we sure that the hs300 counts as 6? It pulls 1 IP address and makes 1 lan bridge I would think that the sense meter would have more issues with 6 individual plugs that have 6 IP’s / 6 lan integration just being a small wireless device, I would have guess the cap would be over wireless bridges and not actual device slots. Could be wrong though.
Had that discussion with Sense in the past. They updated the FAQ to clarify. I’m guessing that the limit is not driven by the number of responses, but by processing bandwidth for each plug.
Is there a limit to the number of smart plugs I can connect to Sense?
The number of smart plugs is limited primarily by Wi-Fi network bandwidth. Typical Sense users can use about 20 smart plugs without issue. Note that each plug of the TP-Link HS300 smart strip counts as 1 smart plug, regardless of status.
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Thanks for the additional insights all,
Good news! My Kasa plugs are back online with Sense. I believe this ultimately was a router issue which was resolved after a once a week scheduled 2am reboot.
Prior to the router reboot I was not able to ping the plugs. Now I can and I’ve taken the advice to reserve their IP addresses to keep them consistent.
Prior to the router reboot I had Network Device Identification (NID) turned on. I had turned it off and on again a few times, but at that time it made no difference. It was off at the time of reboot and remains so.
Prior to the reboot I removed/deleted a single KP115 plug via the Kasa app. Then I proceeded to add it again with a new name. Prior to the router reboot, this made no difference to Sense. After the reboot Sense showed the device with its new name, but with it’s old/prior usage history.
I was aware of the reported ~20 plug limit, however; I understood this to be more of a limit do to router and WiFi performance. I was not seeing any of these performance related issues with my usage. I primarily use these plugs to keep devices off when not in use to save energy and to monitor and understand their consumption when on and in use. I do see merit in the suggestion that the Sense hardware may have its own bandwidth and processing limitations.
I learned of the 5 day routine disconnect reported by other community members, but I have not experienced that to date.
What ultimately brought these plugs back online with Sense? I don’t know. Why prior router reboots, and power cycling the Sense didn’t work is beyond me. However, with a bit of luck, these clues and above in this community thread are a benefit someone else…
Thanks again everyone
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I know I keep harping on this hs300= 1 per plug in the 20 device limit. I see where sense specifically says that in there help section and it says “ The number of smart plugs is limited primarily by Wi-Fi network bandwidth ”.
BUT… I am going to disagree with sense’s
Not saying that a 6 plug device would have the same amount of data as 1 plug.
Example: setup 1- 3x hs300 (18 plugs w/3 ip’s)
Setup 2 18x kp125 (18 plugs w/18 ip’s)
Keep in mind that WiFi is half duplex (until you get to AX) meaning that data can only flow 1 direction at a time…. Each bridge goes … sense … wireless … router… wireless … device…… wireless… router… wireless… sense.
18 wireless lan bridges talking to a sense meter vs 3? Not a chance that the latency would even be close… I’m sure the packets for 3 hs300 vs 18 kp125 also wouldn’t be close.
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I think that WiFi bandwidth part of that explanation is a little hokey. The symptom I saw with too many plugs (including 3 HS300s), was the Sense monitor CPU getting pegged to 99% utilization (diagnosed by support).