The APC gear (at least my Back-UPS 650VAs) periodically do a self-test and give you a GO/NO GO notification.
Not much help if you're powering something that isn't UPS aware, but the UPS does start beeping at you more & more often.
Glad it all went well for you Blues&twos
Mac
Edited to agree with SAAB - I put the date installed on 'em with a chinagraph crayon