Last Wednesday, I went out. I had to stop at Walgreens to pick up a 9V battery for my TENS unit. I put one battery in my TENS unit and went on with my day. When I arrived home, I put the other 9V batteries in the closet. Fast forward to Saturday night 10:47 pm. My smoke/carbon dioxide detector starts going off; then stops. I quickly, well as quickly as I can, get up and check the stove and oven. No gas smell, no heat, no fire. I go back to bed wondering what caused the alarm to sound. 12:16 am the alarm goes off again! I once again get up and check the stove and oven. No gas, no heat, no fire. I even check to see if all the pilot lights are lit. They are. As I was standing there trying to figure out what set off the alarm, it goes off again. I get one of my kitchen chair/stools and carefully climb up on it. I'm looking at the alarm. That's when I see a small tab. I push it and a small container pops out. There's a battery too! I've lived in my apartment for 15 years. The alarm is connected electrically to the apartment's circuits and never had a battery. Last year, when they upgraded the alarm to include a carbon dioxide alarm, they never told me the new ones have a battery! I carefully climbed down from the chair/stool and got a battery from the closet. Then I climbed back up and after a few minutes of maneuvering, got the battery back in the compartment. Then I waited to see if the alarm would go off again....5 min. nothing. 15 min nothing. I went back to bed wondering if that's all it was a dead battery. The alarm has been quiet since. I now know to replace the battery when I change the clocks. That way, I won't have anymore midnight wake up calls! I think back to Wed when I bought the batteries. I had been buying only one at a time. Just what I need for my TENS unit. But this day, they were out of single sets. So I bought a double set. And they were on sale, so actually I bought a 2 double sets. So, at midnight when I needed a 9 volt battery, I had one ready to put in. The details which often go unnoticed, were very LOUD and clear to me this time. Next time, I buy a set of batteries, I'll think about my midnight wake up call and how God made sure I had the extra battery on hand.Sometimes, even unpleasant events can turn into a positive, when we stop and look at the details involved. The next time something unpleasant upsets your routine, look for the positive aspects, you might be surprised at what you will find!