Review on KEDSUM Battery Aquarium Air Pump: Ultra-Quiet Rechargeable Fish Aerator with Dual Outlets - Ideal for Fish Tanks, Outdoor Fishing, Fish Transportation, and Power Outages by Jeff Gopala

These things saved almost all my fish, all but one in the tanks I had these on survived the news-making Texas winter storm of ‘21. Powerful, QUIET, the alert beep is PERFECT for when you are exhausted and sleeping, wakes you up to ensure you don’t lose fish because the pump stops. We charged the first time BEFORE losing power. A long good charge and got a REALLY long use period, 12-15hrs something like that.Next charges were shorter because we had to use the car USB charge and it is SLOW. But still nice long stretches. We were out of power for 36 HOURS total, tank dipped to 44*F from 80*F. Across three tanks, I lost four fish. Out of FORTY. And three of those were in the one tank I did NOT use these pumps in. Just buy it.