Which is better for a smoke detector?

The Ultimate Lithium. Its 25-year shelf life and wide temperature range suit detectors that sit untouched for years. The E91 works but needs replacing more often.

Which lasts longer in a camera or game controller?

The Ultimate Lithium. It has slightly higher capacity and is built for high-drain devices, where alkaline voltage sags faster under load.

Is the lithium pack worth twice the price?

Only if the device is high-drain, used in cold weather, or hard to reach. For remotes, clocks, and toys, the E91 at $5.48 does the job for less.

Can either be recharged?

No. Both are disposable. Recharging them is unsafe.

How long can I store them?

Up to 25 years for the Ultimate Lithium and 10 years for the E91, both in cool, dry storage.

Which handles cold weather better?

The Ultimate Lithium, rated down to -40°F. The E91 is rated only to about 0°F.

Energizer Ultimate Lithium AA Batteries vs Energizer E91 AA Alkaline Batteries

Buy the Ultimate Lithium if the batteries go in a smoke detector, camera, game controller, or anything used outdoors or in cold weather. Buy the E91 alkaline if you just need cheap AA power for remotes, clocks, flashlights, and toys. As of November 6, 2026, the lithium 4-pack is $11.39 at Amazon and the E91 4-pack is $5.48 at The Home Depot, so the lithium costs about twice as much per battery.

Today the Energizer E91 AA Alkaline Batteries costs $5.91 less at its best price.

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