Duracell® Coppertop 9-Volt Alkaline Batteries, Box Of 12

I'm in my last few batteries but these lasted me a good four years. We use these for certain electronics and these last really long. One machine I use them for is a electric muscle massager which uses a lot of power and it's 60 minutes per session. One battery lasts me weeks with continuous use so that means their capacity is really high and they drain slowly. They also offer a guarantee that if you're not satisfied with the product you can call the number in the back and I assume they'll give you replacements. Although these packs can be expensive, it's one of those purchases you buy one time and you're set for years.

There are few things as annoying as your smoke detector chirping in the middle of the night. The last time it happened to me I didn't have a replacement 9V battery and had to deal with the chirp all night. Now I make sure to always have a couple extra Duracell 9V batteries in my junk drawer, just in case. Duracell is my brand of choice. They're long lasting, reliable, and have a long shelf life. They aren't the only good battery brand, but they are the best in my experience.