The battery be connect outside. The electronic fence energiser is compact, modern, designedDetail Information: Power supply: 12 volts Consumption: 0.05A~0.25A / hour Voltage Vacuum: 10000 volts Delivered power vacuum: 6.2 joules Power output at 500 ohms: 0.5~2.5 joules Effective length: 40 km Plastic case. Dimensions: 275x220x100 mm Weight: 2.5 kg ELECTRONIC FENCE CONTROLLER