SOBO Aquarium AC/DC Air Pump SB-10000 2nd Generation Features: - 2nd Generation Lithium Battery 4400mA! - 12Watt with 2x5Liter/min Air Output - 0.016Mpa Pressure - Energy efficient design; high output/wattage - Will last for 20hours continuous mode without AC i.e. during power failure/disruption. - Will last for 40hours intermittent mode without AC i.e. during power failture/disruption. - Suitable for home based aquarium tank and never need to worry about power failure. One of the must-haves of small backyard/home based aquaponics system is this AC/DC air pump. This air pump is able to provide you a 20 hours of service using its internal maintenance-free battery in case of power failure/outage. And when the power comes back it will recharge itself. All this happens automatically as it switches between AC or DC mode depending on whether there is incoming power. The pump also operate with low noise suitable for your home. Remember to install it well above your water level to prevent backflow of water into the air pump. 8-10 hour charging time.