SONOFF SenseGuard SNZB-03PR2 Zigbee Motion Sensor

Basic motion sensor with a light, but fairly limited beyond that!

The SONOFF SenseGuard SNZB-03PR2 Zigbee Motion Sensor functions as a basic, straightforward motion sensor that includes a built-in light. It detects movement as intended and triggers the indicator/light feature when motion is registered in the area.

​However, if you are looking for advanced features or more complex smart home automation capabilities, it falls a bit short. It is essentially just a standard motion detector with a light and doesn't do much else beyond its core function. Overall, it gets 3 stars for basic reliability without extra bells and whistles.

Carl Douglas

August 13, 2026

Excellent Home Assistant Motion Sensor

I’ve used Home Assistant for several years and have quite a few SONOFF devices throughout my house, so I’m very familiar with the brand. I’ve always had good experiences with their products, and this little Zigbee motion sensor has been no exception.

I really like the compact size and the magnetic base. In my case, I was actually able to stick it directly to the wall because of the metal studs behind the drywall, which made installation incredibly easy.

Pairing with Zigbee2MQTT was just as simple. After pulling the battery tab, I was able to add it right away. It was properly recognized and immediately exposed both motion and lux readings. Zigbee2MQTT also gives me the ability to adjust the detection time all the way down to five seconds. That’s much shorter than most motion sensors I’ve used, and I absolutely love having that option for automations where I want a quick reset.

My only minor complaints are the coin cell battery, since I’ve been trying to move away from those in my smart home devices, and the battery cover was a little difficult to remove.

Aside from those small issues, I’ve been extremely happy with it. Detection has been responsive and it’s been rock solid in Home Assistant so far.

Works great and adds motion based actions to your system

Setup was simple and just followed instructions to pair, Alexa found it, added it and then it was setup for an entry light, response is delayed by one second, from motion to light coming on.

Fully compatible with Zigbee built into the Echo Hub 8” display.

Battery life has been great so far and it’s an inexpensive way to add motion function to your smart home automation.

Magnetic mount allows you to adjust the angle and direction for motion detection needed.

Small and unobtrusive, can be placed on walls or furniture.

Worked out of the box with Home Assistant.

I am just now getting into home automation and this is my second Zigbee sensor I have adapted to my Home Assistant. The first one was a bit wonky, but after taking the battery sticker thing out and going into Home Assistant, it was found and worked with nothing special to do at all. I was easily able to add the sensor readings to my dashboard. I use the luminance sensor to turn on a lamp at dusk and the motion sensor to activate the lights for a room. It does have a one or two second lag, but it has not skipped a beat.

I cannot talk about the battery life yet since I have only had it up for about three weeks, but I was really, really surprised it just worked straight out of the box without any hiccups at all. If you have home assistant and a Zigbee USB dongle (or other way of getting ZigBee) then I suspect you will also not have any problems adding / using this sensor.

Works well for now.

I have this hooked up to my Home Assistant and it is working right now. A quick Google search will show issues with SONOFF devices and HA.

I have mine setup to alert me when there is motion detected.

The only thing I don't like is that the battery is not standard. If they could make this work with a standard battery, that would be great.

I do like that the base is magnetic and there is a 3M mounting circle to attach it to different surfaces.

Easy to mount

This is my first sensor from this company, and so far I’ve been very pleased with it. I was able to connect it to my Polisy controller from Universal Devices. It has worked reliably and gives a good first impression in terms of both quality and ease of use. One of the first things I noticed is how compact it is. The small form factor makes it easy to tuck away in places where it isn’t very noticeable. Whether you’re mounting it on a wall, shelf, cabinet, or another surface, it doesn’t draw a lot of attention to itself. The included double sided tape works well. Since the sensor is lightweight, I had no issues getting it to stay attached to a smooth surface. It feels secure enough that I don’t anticipate it coming loose during normal use.

My favorite feature is the magnetic mounting base. It gives you a lot of flexibility when positioning the sensor because you can easily adjust the angle after it’s mounted. It actually reminds me of the magnetic ball mounts used on some outdoor security cameras. Being able to point the sensor exactly where you want without removing and reinstalling it is a very nice design feature. Accessing the battery compartment took me a minute because the two halves fit together very snugly. That’s not really a complaint since the tight fit probably helps the overall durability of the sensor, but it did require a little more effort than I initially expected.

The battery itself is a type I’m not very familiar with, so I’ll probably need to order replacements when the time comes rather than picking one up locally. Fortunately, that’s not something I’ll have to worry about very often. Most importantly, the sensor itself has performed well. It responds reliably, and I haven’t experienced any false readings or connectivity problems. It simply does what it’s designed to do.

Overall, this is a well designed sensor with a compact size, flexible magnetic mounting system, and reliable performance. The thoughtful mounting options make installation easy, and the quality feels very good for the price. At under twenty dollars, I think it offers excellent value and I would definitely consider getting additional sensors from this company.

Affordable and reliable motion sensor

Quick Facts:

Power Source: CR2477 Battery

Protocol: Zigbee 3.0

Mount Type: Magnetic Base

Sensor Type: PIR (Passive Infrared)

Supported Entities: Motion, Illuminance, Battery Percentage

I got this because I had automations in my laundry room when the doors open to turn the lights on, but when my wife is doing laundry the lights would shut off while she was working. Using this the lights stay on as long as she is moving. For full disclosure, I am a fan of the Sonoff brand and have several of their sensors because they are affordable and reliable. This one is no exception.

The device comes in two separate parts; the sensor itself and a magnetic base. The magnetic base and the back of the sensor are both curved, allowing you to point it in any direction you want without having to use a finicky pivot. I used the included 3M adhesive pad to mount it to the drywall in the corner of my laundry room near the ceiling. The sensor also has a built-in illuminance sensor. This is a PIR sensor, so it does not detect occupancy if you are not moving. This characteristic makes it perfect for a laundry room, although it would not be as appropriate for a living room, for example.

The sensor itself breaks apart into a curved end cap. Under that is a battery compartment that you can remove with a coin. The battery is a CR2477 coin cell. Unfortunately, this is the only device I have that uses this particular battery, meaning that it is yet another battery that I need to stock up on. The product listing indicates that the battery should last 3 years, so I will probably wait until it is reporting 50% or less before ordering. The piece of plastic that keeps the battery from being activated before your first use rests tight along the inside of the battery compartment, making it very difficult to remove at least with my fingers. I had to get a pair of needle-nose pliers to pull it out. The battery compartment takes a little more pressure than is typical for this type of device when you twist it back on. This is just a tight plastic fit, but I mention it because I do not want you to think you are about to break it.

There is a button located on the exterior of the sensor and is easily accessible. Pairing was a little bit challenging, as most Zigbee devices show up in Home Assistant within seconds of going into pairing mode. For this one, it took several minutes. I thought perhaps it was not working and tried to force pairing mode by holding down the button underneath the sensor for 5 seconds. I actually did this a few times before it paired. Once paired, it showed up in Home Assistant correctly and with all of the appropriate entities, including an illuminance sensor. I do not have a use for the illuminance sensor in this particular room, although I do have motion sensors in other rooms where it would have been nice to have. I do not believe the pairing issue is a signal strength issue, as it has been extremely reliable once paired. I also do not believe it was a compatibility issue because my Zigbee hub is a Sonoff Zigbee 3.0 USB dongle.

I do have one minor issue with it in the laundry room. I have it pointing in the direction of the washer and dryer, and the dryer door heating up appears to turn on the lights in the room. It only happens when the dryer door first heats up, and I do not have the same issue as the dryer door cools down, so this is a minor issue for my use-case. The prices are at the low end for similar sensors, making this a great value.

Positives:

✅ Affordable

✅ Reliable

✅ Curved magnetic base allows easy aiming

✅ Includes a built-in illuminance sensor entity in Home Assistant

✅ Exterior pairing button is easily accessible

Negatives:

❎ Requires a less common CR2477 battery

❎ Battery activation pull-tab difficult to pull

❎ Slow pairing process

❎ PIR sensitive to heat changes in the room.

Smooth connection to Home Assistant with ZHA integration. Didn't need any quirks script.

This motion sensor is working fine with the current Home Assistant, using ZHA integration and a third-party Zigbee USB dongle. It shows illumination and lets me change occupied-to-unoccupied cooldown in seconds, with 5 seconds working fine. PIR range was good, dozens of feet, with quick response on first motion. It has a dim LED that flashes, but can only been seen in the dark or very close with lights on. Illumination is handy to adjust light brightness to existing light levels. Sensor has nice magnetic mount to base, with easy adjustment and removal to change battery. Pairing worked fine, like any other Zigbee device. I didn't need to install any quirks as mentioned elsewhere. I did have to press the button a few times while changing the cooldown, to get it to update, because the device sleeps when there's no motion. It worked fine with a more common CR2450 battery size, due to having a foam pad on the battery cover that keeps the battery pressed in. It also worked fine with an LF2450 rechargeable battery. Out of curiosity I checked whether it would pair with Tuya and a Zigbee hub, but it didn't show up.

Karin S

June 26, 2026

You should probably know more than I or have done ur research

First the written directions are typed out in such a very odd way. After the cover page on the next page you have your QR code and it gives you directions to scan it in English at the top and below you it in 6 more languages filling the page. So you move through the document and the next 6 steps in the exact same way. Which means what should be written together in one language in maybe 2-4 pages now you have to go through all 20 and find your language for all the different steps within the steps. The steps within the steps have a little "i" over them. The directions on the leaflet tell you very very little and you will need to use the manual from the QR code anyway unless maybe you have one of these or something similar. 2nd Mine would not power on. I did everything in the directions. Tried the battery in both positions and repeated the steps a couple of times. So I looked for a troubleshooting area both on the webpage and the leaflet. There's none they have a FAQ on the website but it's exactly what it says and of no use. There's no contact information there either and I went to the bottom of the webpage to see if it was there (like some sites do) there was not. I did find it on their home page and I have sent a contact form that was available. Right now I'm waiting.

☆☆I'm a newbie to the smart home things. I've just recently started use smart things. I've had my Alexas but really do very little with them and don't control anything with them like I do with smart things. But now here's the catch. I saw smart things on the listing and all I cared about was it turning on a light when it detected motion and now if I'm reading the manual right my phone app will not be enough. Still learning so I can't say for certainty but I'm saying it here for any other newbies out there. I of course now have to wait to see if I can get mine replaced or what they will do. It will say what their customer service is like at least. It absolutely appears sturdy, well made, and I've heard nothing but good things about this brand. I like the flexibility the base gives you by it being a magnet. Of course they provide screws if you want a more permanent position and a 3M sticker if you don't.