Backup power for aquarium heater, air pump, and filter

[Anonymous user]

Except for one air pump which has built-in backup power from 2 "D" batteries, I have not been able to locate any product advertised for powering aquarium products like heaters and filters when the AC power fails. The pet shop has been of little help. Does anyone know how UPS batteries of different wattages would work to keep aquarium accessories going for electric outages of 12-24 hours? The heater I have is rated at 50 watts. I have an electrically operated filter that does not state a wattage. Any ideas for backing up my sensitive fish tank against electrical outages would be appreciated.

[TheNotoriousKMP_apc]

I don't think you're going to find anything that will be of use to you for under 5000 and you'll need a lot of space to attribute for the runtime requested.

I think you may want to get a UPS just for the initial power failure, then a generator for when the failure kicks in.

[Anonymous user]

Thanks, Notorious K, but do you or anyone else know how long a less expensive UPS backup battery (say, something that is supposed to keep a computer going for up to 30 minutes) would actually keep going if it only had to power a thermastat-controlled heater and a filter being used in a small tropical-fish aquarium? I am assuming it would keep going much longer if it was powering smaller appliances. Am I right about that?

[TheNotoriousKMP_apc · Accepted solution]

Under a 50W load it's going to last 2-3 minutes before the UPS senses that it's not powering anything substantial and powers itself off. At 50W, I think the largest runtime you can get is no more than 2 hours.

But mainly, I think the heater due to the DC motor will trip the UPS into Overload.

[Anonymous user]

What you say must be right because, from Googling, I find no aquarium expert suggesting what I was suggesting. A few say you can modify an automobile battery for backup power, but I'm not up for that. If you have any other ideas, let me know. Thank you again for your expertise on this subject. LarryS