The sensor is powered by a built-in rechargeable lithium-ion battery which will be charged by the solar panel, so no need to replace the battery. (PS. the sensor also can be powered by the DC5V-12V power adapter or by the extra solar panel if the sensor is installed indoors or in dark areas).400 Meters Solar Wireless Driveway Alarm
Wireless Transmission Range: 400 Meters (line of sight)
