Energizer Ultimate Lithium AA Batteries vs Energizer Ultimate e2 AA Cylindrical Lithium Battery

Both are Energizer lithium AA cells built on the same L91 chemistry, so performance is close. The Ultimate Lithium is the better all-round pick: it is rated for up to 25 years of storage, comes in a 4 pack, and is marketed for smoke detectors, cameras and high-drain devices. The e2 is a 2 pack aimed at cameras and flash units, with a 20-year storage rating. Buy the Ultimate Lithium unless you only need a pair for a camera.

• Choose the Energizer Ultimate Lithium if you want the longest shelf life, a 4 pack, and a cell rated for smoke detectors and other high-drain household devices.
• Choose the Energizer Ultimate e2 if you mainly need a spare pair for a camera or flash and want the smaller pack.