Are you looking for a small, round shape battery for Dog Collar, Camera, Glucose Monitor? Does it look like the picture on the left? If yes, you are looking for the CR1/3N Lithium Battery, also known as a 3V Lithium Button Cell battery. This CR1/3N lithium battery has a high energy density design with the benefit of lightweight and powerful. At the same time, it provides a long service life and stable power output. It has long shelf life of 10 years. It is commonly used in Aimpoint Sight battery, dog collars, keyless entry, and many other electronic devices.
You can find these batteries in your local electronic stores, but they may not carry the correct model number. If they do have it, it will be very expensive, from $4.99 - 9.99 per piece. However, you can buy the CR1/3N button cell battery online easily and for a fraction of the store price. You can search for the battery using the names: cr1 3n battery, cr1/3n battery equivalent, cr1/3n battery cross reference. Many different brands make this battery: Energizer, Varta, Evergreen, Duracell.