An animal watering device (2) comprising a trough (4) for holding water, a water conduit system (6) in fluid communication with the trough (4) and arranged to be connected to a water supply (8), an electric power consuming water level control system (24) comprising a controller (26) and at least one water level sensor (28, 32, 34) arranged to sense a water level in the trough (4), and an electric power unit is provided. The electric power unit comprises an electric generator (36) and an electrically chargeable unit (38). The water level control system (24) is connected to the electrically chargeable unit (38). The electric generator (36) is connected to the water conduit system (6). The electric generator (36) is arranged to be driven by water from the water supply (8) and to charge the electrically chargeable unit (38).