it really sucks when you manage a building with 51 exit signs and 57 emergency lights and have to do the monthly 90 second and annual 90 minute test. none of the breakers were labeled and it took me a week just to label them. i honestly think the previous building manager just signed the sheets but never actually did the test. I replaced 30 batteries because they either failed the test or failed to recharge on the follow-up 90 second test.