Solarrific G4042 3.5 Rechargeable Air Pump Kit for Fish Pond The system is designed for oxygenating the water to create a healthy environment in any outdoor water body that keeps fish, such as outdoor aquarium, garden pond, and garden water feature. The power supply of the air pump is provided by a battery which is charged by a solar module, so that the air pump is capable of working at night and on overcast day. In order to make the pump work by solar energy, the solar panel needs to be placed in the sunlight with its solar cells facing the sun as much as possible. A full battery charge during the day (without day running) can provide up to 8-10 hours of pump running at night. A full battery charge during the day (with day running) can provide up to additional 2-4 hours of pump running at night. Kindly note that some stored energy is also consumed because there are some cloudy hours in the sunny day time. ATTENTION PURCHASER: This battery is shipped with the positive terminal disconnected for safety and quality purposes. Please open the battery and attach the positive cable to the terminal as shown in the last photo, and attach the loose cable to the positive terminal