Sonoff is known in the smart home world for delivering affordable, DIY-friendly devices that often punch well above their price. While their AC-powered devices aren’t always AU/NZ certified, their battery-powered sensors—like the SNZB-03 Zigbee Motion Sensor—are a safe, cost-effective choice for automating your home.
If you’re building a budget-conscious smart home with Home Assistant, SmartThings, or Amazon Alexa Zigbee hubs, this tiny sensor is worth a look.
Positives: What’s Great About It
- Compact Size: The SNZB-03 is one of the smallest Zigbee motion sensors, perfect for discreet placement in tight corners or above door frames.
- Good Battery Life: Powered by a CR2450 coin-cell battery, it can last 6–12 months, depending on usage.
- Broad Zigbee Compatibility: Works well with most Zigbee hubs, including Home Assistant (ZHA & Zigbee2MQTT), SmartThings, and Alexa.
- App Flexibility: You can use it via eWeLink app (Sonoff’s native app) or integrate into multi-brand Zigbee ecosystems.
Drawbacks: Things to Keep in Mind
- No Lux Sensor: The SNZB-03 can’t measure ambient light, so you can’t use it to automate based on day/night conditions.
- No IP Rating: Not weatherproof—indoor use only.
- Limited Mounting Options: Doesn’t include an angle-adjustable bracket, and the sensitivity can’t be fine-tuned.
- No Native HomeKit Support: Works with HomeKit only through compatible Zigbee bridges like Homebridge or HomeKit supported hubs—no native pairing.
Ecosystem Consideration
Unlike Tuya-powered devices, Sonoff runs on its own ecosystem – eWeLink – but the SNZB-03 is fully Zigbee-based, not Wi-Fi, so it’s not tied to the cloud.
This means you can skip the eWeLink app entirely and integrate the sensor directly into your Zigbee network, with no internet dependency if you’re using platforms like Home Assistant or SmartThings.
That said, Sonoff isn’t part of the Tuya ecosystem, so you won’t get cross-compatibility with devices like Grid Connect or Mercator Ikuü. But that’s fine – most users will run it as a standalone sensor or part of a custom automation hub.
Final Thoughts
The Sonoff SNZB-03 is a solid no-frills motion sensor that offers great value for DIYers, especially those using Home Assistant, ZHA, or Zigbee2MQTT.
That said, one downside I’ve experienced is the use of a CR2450 coin-cell battery. These aren’t as readily available as AA/AAA batteries and tend to be more expensive. Worse, when the battery starts to run low, the sensor can produce false triggers or miss motion events entirely, which can undermine your automations and reliability.
If you’re just after a basic motion sensor to control lights or detect presence indoors, the SNZB-03 is still a top-tier budget option.
If you’re looking for a simple sensor to automate lights or track motion, this is a top-tier budget pick. However, if you need lux sensing, angle flexibility, or weather resistance, you may want to consider Aqara P1 or IKEA VALLHORN instead.
Common FAQs
Can I control lights without a hub?
No-you’ll need a Zigbee hub to connect this sensor to your smart lights or automations.
Do I need to use the Sonoff Zigbee bridge?
No-it works with any Zigbee hub, including SmartThings, Home Assistant (ZHA/Z2M) using USB Dongle, Amazon Echo Zigbee hubs, and more.
Does it work with Home Assistant?
Yes-it integrates perfectly with ZHA and Zigbee2MQTT.
Can I use it with Apple HomeKit?
Yes, but only indirectly, via a HomeKit-compatible Zigbee hub, like Homebridge with Zigbee plugin.
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