I purchased several Azoo Non-Stop Air Pumps for my fish aquariums. This air pump has a battery backup so that when the power is cut off, the pump still works by battery power. The pump has two outlets that you can use. I have a bubble wand connected to one outlet through silicone tubing. There are two speeds, low and high.
As long as the power is on, this air pump works just fine. But I have found on several occasions that when I lost power in my house (which does happen occasionally), the pump works for a few hours on the battery and then it quits. You are supposed to get up to 20 hours of battery power when the battery is fully charged, and I have not gotten anywhere near this amount of time. Of course, I haven't had my power shut off for 20 hours, but even after a few hours, the pump shuts off. I have two of these pumps, and they both have done the same thing, with the battery power cutting off after just a few hours.
I still use this pump, and as long as the power is OK, the pump runs fine. But if the power should shut off, the pump will only run for a few hours and then quits. Since I got this type of pump to have battery backup, it really isn't giving me what I need, which is a disappointment. I think my husband called the company about this, but it was past the return period so there was nothing they could do.
All in all, I am not pleased with the battery backup on this pump. As far as I'm concerned, it runs just like any pump without the battery backup feature.