I've always heard to replace your UPS after a lightning strike but I can't find anything reliable online confirming this. We took a lightning strike a few weeks ago that killed devices (mostly network switches) that were directly connected to various APC UPS (most are Back Ups Pro 1500 with battery packs). The UPS seem to be working okay but should we replace them anyway? Thanks.
The UPSs are designed to shunt a spike to the ground, or if the spike is too significant, the MOV will break to prevent damage to the attached equipment. If the MOV breaks, the UPS will not function. Since the UPS are still working, that indicates if they did experience a spike, it was passed to the ground, and the UPS are safe to use.