Best Battery powered air pump for power outages?

After seeing all the power outage threads I’ve decided to buy a battery powered air pump so I will at least be able to keep the water oxygenated and moving if the power goes out. Ideally I’d like it to have an adjustable air flow and for it to be under $35. The pump would be used for either a 20 gallon tank or a 40 gallon tank. So with those things in mind, what battery powered air pump should I get?

 

I had two of these and they were literally, life saving for my tanks during our 36 hour outage. Each unit has two air outlets and it comes with line and stones and the stones are really good fine bubblers. They take a long time to charge BUT ran for TWELVE HOURS STRAIGHT for me.

They give an audible beep when running low and that is vital when you might be crashed out exhausted and miss a silent one. We charged them for shorter than the initial charge in our cars out of necessity...but still got 4-7 hour stretches of use. And they were quieter than my TetraWhisper pumps!

And you can make ANY air pump adjustable flow, with a cheap regulator valve. But in an outage you want good strong airflow.

KEDSUM Aquarium Air Pump, Rechargeable and Portable Fish Tank Air Pump with 2 Air Outlets/Stones/Tubes/Check Valve for Fish Tank, Outdoor Fishing, Fish Transportation and Power Outages https://www.amazon.com/dp/B07SB4MLJ...abc_JGM4Z4JYZMZXRS44GK4T?_encoding=UTF8&psc=1
The valves:

30 Pieces 2 Way Fish Tank Air Pump Aquaculture T Shape Control Valve Plastic Aquarium Hose Connector for 4 mm Air Tube (Blue) Amazon.com : 30 Pieces 2 Way Fish Tank Air Pump Aquaculture T Shape Control Valve Plastic Aquarium Hose Connector for 4 mm Air Tube (Blue) : Pet Supplies

 

I have one from Walmart (from the fishing section, used for live wells), but there are some on Amazon that might be good too.

I would stay away from any rechargeable ones, since you probably will be wanting to charge your phone, not a fish air pump IF you find power during an outage.
And good old alkaline batteries are also a good idea. Li-ion rechargables might be good, but the NiHM ones are JUNK!

 

Thanks everyone, I think I’ll try the rechargeable pump, but I’ll also get a different pump that’s not rechargeable so I won’t need to charge them both during an outage.
Does this pump look good?
https://www.amazon.com/Uniclife-Aqu...air+pump&qid=1613826929&s=pet-supplies&sr=1-4

 

I have this one, initially used when I made a trip to visit my son and setup a tank for his wife, brought along live fish and media. Took about 36 hours start to finish. The pump worked fine. Also, when I had a 12 hour power outage used on my Discus tank.
Amazon.com : Azoo AZ15001 Battery Operated air Pump : Pet Supplies

Good Luck!