Airport utility goto settings turn on WiFi scanner. Some AP’s have a scanner built in so it will show u from the AP overlapping coverage signal.

Install conduit, run fiber with media converters. Fiber is so easy u can trim it out with a pair of scissors and slap on a mechanical end and would still be 100x better than the money ur wasting on a “repeater”.

No way is this working as an ups. It may work as a back up for voltage drop, an ups works as a sure protector, monitors incoming voltage, power conditioner and battery back up. 2 12v 7ah is barely enough for a few devices. Most take 4 to handle the wattage. Be safe.