The first Lego Smart Brick sets, based on Star Wars, have some technical limitations, as many of their sensors, including the sound-detecting microphone, the ambient light sensor, fine distance measurement, position, and orientation, are not yet available. The company's Smart Brick app reveals that the device's built-in microphone is currently disabled and will require an update if that changes. The Smart Bricks also lack many other sensors, such as an NFC reader that registers nearby Smart Tiles and motion sensors. However, the batteries in the Smart Brick are not user replaceable and require special attention to protect the battery from draining too fast. The device only offers around 45 minutes of active play and puts itself to sleep within three minutes if it's idle, but will also go into a deep sleep after 13 hours.