UPS Coil Whine(?)

[Tethandros]

I inherited an APC Back-UPS XS 1500 a few years back, and it's had this issue since I got it.

Every 9-10 seconds, it emits this weird "cricket" sound; I finally decided to record it, since I'm not sure what regular coil whine sounds like: here.

This hasn't affected the UPS' performance as far as I can tell, and it doesn't seem to be getting overly hot.

Could the batteries need replacing instead? I would think the performance/capacity would diminish if that were the case.

 

[jrweis]

I believe that it is the charging circuit that's giving you the noise, not the batteries!