August Motion Sensor Review

Who is the August Motion Sensor for?

The August Motion Sensor is designed for homeowners who already own an August Smart Lock (Wi-Fi or Pro model) and want a more reliable hands-free unlocking experience. It is ideal for those who find smartphone geofencing too slow or inconsistent, especially in multi-story homes where the phone's GPS can be inaccurate. The sensor is also useful for people who frequently carry groceries or packages and need the door to unlock as they approach, without fumbling for a phone or key.

It is not a standalone product. You must have a compatible August Smart Lock and the August app installed. The sensor is best suited for single-family homes with a clear, predictable path to the front door. It is less effective for apartments or homes where the door is approached from multiple angles or through a shared hallway.

Performance and Reliability

The August Motion Sensor uses a passive infrared (PIR) sensor to detect motion within a 30-foot cone. When it senses movement, it sends a signal to the paired August Smart Lock to initiate the auto-unlock sequence. Based on aggregated owner reviews, the sensor significantly improves the consistency of auto-unlock compared to relying solely on smartphone geofencing. Users report that the door unlocks reliably when they are within 10-15 feet, which is faster than the typical geofencing delay of 10-30 seconds.

However, the sensor's performance is highly dependent on placement. It needs to be mounted on a wall or door frame facing the direction from which you approach. If you approach from the side or from behind the sensor, it may not trigger. Some users have noted that the sensor can be triggered by pets or passing cars if placed too low or facing a street, leading to accidental unlocks. There is no adjustable sensitivity setting in the app, so placement is critical to avoid false triggers.

Build Quality and Installation

The sensor is built from white plastic with a compact, unobtrusive design. It feels solid and well-made for its price point. The unit is weather-resistant but not fully waterproof, so it should be installed under a covered porch or overhang. The included adhesive strip is strong enough for most surfaces, but some users have reported it failing in extreme heat or cold. For a more permanent installation, the sensor can be mounted with the included screws.

Installation is straightforward. You pair the sensor with the August app, which takes about two minutes. The app guides you through placing the sensor in the optimal location and testing the trigger zone. The sensor runs on a CR123A battery, which August claims lasts 6-12 months depending on usage. Battery replacement is simple with a twist-off cap.

Alternatives to the August Motion Sensor

If you do not have an August Smart Lock, the sensor is not an option. For other smart lock brands like Yale or Ring, you would need their respective motion sensors or rely on geofencing. For August users, the main alternative is to skip the sensor and rely on the lock's built-in geofencing or use the keypad or app for manual unlocking. The keypad is a more reliable backup for guests or service providers, while the sensor is best for the primary user's daily routine.

Another alternative is to use a smart home hub like Samsung SmartThings or Hubitat to create a custom automation based on a separate motion sensor. This approach is more flexible but requires more technical setup and may introduce latency compared to the dedicated August sensor.

What to Check Before Buying

Before purchasing the August Motion Sensor, verify that your August Smart Lock model is compatible. The sensor works with the August Smart Lock Pro (3rd Gen) and August Smart Lock Wi-Fi (4th Gen). It does not work with the August Smart Lock (2nd Gen) or the August Wi-Fi Smart Lock (with built-in Wi-Fi). Also, ensure you have a clear, unobstructed path to your door from one direction. If your door is approached from multiple sides, the sensor may not trigger reliably.

Check the weather conditions at your door. The sensor is not rated for direct rain or snow exposure. If your door is fully exposed, consider a different solution. Finally, make sure you are comfortable with the sensor's placement, as it will be visible on your door frame or wall.

Mistakes to Avoid

A common mistake is mounting the sensor too high or too low. The optimal height is about 4-5 feet from the ground, pointing toward the approach path. Mounting it too high can reduce detection range, while mounting it too low can trigger on pets. Another mistake is placing the sensor facing a street or sidewalk, which can cause false triggers from passing pedestrians or vehicles.

Do not rely solely on the sensor for security. It is an unlock convenience feature, not a security sensor. It does not detect intrusion or send alerts for motion. Also, avoid using the adhesive mount in direct sunlight or extreme temperatures, as it may fail. Use the screw mount for a permanent installation.