Designed to operate outdoors in most weather conditions. Fully self-sufficient using solar power to charge an internal battery – no external power supply required. 0.2 Joules of stored energy that allows the user to power up to 3km of multiwire fence or up to 3 acres of property. The S20 automatically runs a night mode where the pulse rate is lengthened while animals are more subdued. This will extend the battery life and maintain good voltage on the fence during daylight hours. Can be mounted on a wall, on a wooden post or can sit on the ground giving the user the ability to use the unit for permanent or portable fencing. Large rotary dial makes it simple for switching the unit on and off and identifying if the unit is on or not from a distance. Impact resistant plastic lens helps protect the solar panel prolonging its life in operation – cleaning the lens regularly will help the energizer run more effectively. LED light flashes with each pulse to help indicate that the unit is going. Internal 12V 5AH rechargeable battery included. Dimensions: 90mm (w) x 100mm (h) x 70mm (d). The expected life of your solar energizer battery depends on a number of variables: The battery age expectancy is normally five years if kept between 0 – 30 °C (and with at least a 70% charge) at all times. Battery life expectancy will be reduced if: the battery is left unused for a period and allowed to self-discharge, the solar panel does not get sufficient sunlight (some regions have less sunlight hours). Again, this will allow the battery to discharge stored at an extreme temperatures (hot or cold), causing the battery to ‘age’ more quickly.