Most any UPS that has a user replaceable battery can be swapped to 12v lifepo4 batteries. they won't likely fit, but I took the two 12v lead acid batteries out

Most any UPS that has a user replaceable battery can be swapped to 12v lifepo4 batteries. they won't likely fit, but I took the two 12v lead acid batteries out of my UPS and extended the wires out the back and to a new shelf that holds two 12v lfp4 batteries. You should get 12v lifepo4s that have built in BMS to protect them from over/under charge. Mine works great and I added a lot more watt hours to it. The only thing that won't work well is the battery level percentage indicator since lfp4 don't read the same as lead acid.