Keep them on hand
This type of battery lasts a long time so you forget how many are in all the alarm sensors around the house until a buzzer or a phone call wakes you up in the middle of the night because one of the batteries has died and the system signaled the monitoring service. I should probably replace them on a schedule like the smoke alarm 9v batteries. The original battery lasted 6 years, others are still good, I should replace them all with these fresh ones.
Rating: 5 stars