I have a 350W APC UPS and use a small bank of LiFePO4 3.2V Nominal batteries with it, instead of Lead batteries.
I'm about to replace it with another bank of LiMn02 3.8V nominal voltage. This will increase the voltage needed to charge the battery from 13.5 or so, to 17.5 or so. The bank will be 1980 Whr, but, I will seldom pull it down much over 1000Whr. It feeds my laptop and modem for now. Trying to stop lightning and power surges from outages is where I am headed, as soon as I get the axial flux alternator finished and installed in the Lenz2 VAWT.
How can I check the output of the charger inside the UPS, to see if it can handle this chore?
The specs I found do not state the charge voltage of the internal charger, only how long it takes to charge >15 seconds for the small SLA typical UPS battery.