I use these batteries for the computers on my bikes. When they wear down, I usually just go to ***** and pick up 1 or 2 new ones made by Eveready or Duracell. I've had to return these 3 times because, even though they are new, they are already very weak. With this experience, I've started to check them as soon as I open them, with a battery tester. These brand name products test barely in the green zone. When I saw these on Overstock, I thought I'd give them a try. Wow. They test fully in the green on my tester. I bought 10 so I hope I can use them before they get old.