MEAN WELL 24V 20A Uninterruptible DC-UPS Controller Module DIN Rail Type

They Just work!!!

This and an NDR-120-24 just got my marine aquarium through hurricane Milton. (44 hrs without power)I ran a typical UPS with an inverter on brand new 8ah batteries for 71 minutes before the UPS died. After moving those batteries to the DUPS-20, and moving my 24v power heads from their bricks to the NDR, I got an additional 8 hours out of those batteries.Important notes for the Meanwell DUPS-20.You can't hot swap batteries. If the batteries die, you need 24vdc to "jumpstart" the DUPS-20.If the voltage in is less than the battery voltage, it will switch over to battery until it discharges the batteries below the voltage in level.With no built in gauge on the DUPS-20, this isn't obvious, and may lead to thinking it's broken.If your equipment has an input tolerance of for instance 20-30v it's easy enough to simply adjust the output of your power supply to match the voltage of your fully charged batteries.

I have their 24V power supply and never had an issue.