Curious the discussion from this thread m.

https://www.geekzone.co.nz/forums.asp?forumid=48&topicid=315112&page_no=1#3249102 

Specially:

Yoban: noroad: 

https://www.aliexpress.com/item/32856831739.html Just add a small car battery. These things are very quiet, there is a little bit of fan noise when they are recharging after an outage but not much.


I followed @noroad guidance a while back and have this model plus this battery (55ah) as my UPS in home rack at 160w I am getting about 60min which is less than the "math" would suggest, but this could be due to battery getting drained to empty a couple of times and as such looking to upgrade size.

A couple of points on the inverter:

it also charges of which very few do, so once connected it is set and forget.
as mentioned, some fan noise when on battery power and charging back up the battery when mains restored
it does have an alarm with no switch off capability when voltage from battery gets too low.
Certainly, a good option for standby power supply.