I recently bought a 2u 2200VA APC Smart UPS on eBay, it works great, but the fans started to make a grinding/squeaking sound. So its time to replace them.
APC apparently use a few different fans in their UPS’s, so you’ll need to open it to confirm what ones are inside. Mine contained ‘AD0824LB-A70GL’ 80mm 24v 90mA fans, but the only replacements I could find are used for $30 plus shipping from china. I did however find 80mm 24v 130mA fans at my local electronics store.
First things first: Shutdown everything thats connected, shutdown the UPS, disconnect the power, pop the front panel off and disconnect and remove the battery.