Energizer Ultimate lithium battery L91 AA 1.5V (blister pack of 4) - L91ULTIMATEB4

The Energizer Ultimate Lithium L91 (AA / Mignon size) is the flagship among 1.5V batteries and is regarded as the world’s longest-lasting AA battery for high-tech devices. Unlike conventional alkaline batteries, it is based on advanced lithium iron sulphide (LiFeS2) chemistry, which offers significantly higher energy density, lower weight and extreme temperature resistance. The pack of four is the perfect quantity for digital cameras, flash units, modern smart home cameras or GPS devices.

Key features at a glance

• World’s longest-lasting AA battery: Delivers up to 11 times more photos than standard alkaline batteries in energy-intensive devices such as digital cameras and ensures maximum runtime.
• 20-year shelf life: The battery retains its charge for an extremely long time (approx. 95 % after 20 years), making it the ideal backup for emergencies, torches and disaster preparedness.
• Extreme temperature range: Works even where others give up – from Arctic -40 °C to extreme +60 °C, indispensable for outdoor sensors in winter.
• Ultra-light: Weighs around 33 % less than a standard alkaline battery (approx. 14.5 g vs. 23 g), which makes a noticeable difference for portable equipment such as handheld GPS devices or head torches.
• Leak-proof: The robust construction prevents liquid leakage and protects expensive equipment (e.g. expensive photography gear) from corrosion damage.
• 100 % Compatible: It has exactly the same dimensions as a standard AA battery and 1.5 volts of voltage, so it can directly replace any ordinary "Mignon" battery.

The standard for Blink cameras & photography

The Energizer L91 is the officially recommended battery for many wireless security cameras such as the Blink Outdoor / Indoor series or Netatmo devices. These cameras absolutely require the high voltage level and cold resistance of lithium to achieve the promised 2-year battery life. Photographers also swear by them for clip-on flashes, as the flash recycle time is significantly shorter than with alkaline cells due to the lower internal resistance.
 

Features

FAQs about the Energizer Ultimate Lithium L91

Can I recharge this battery?

No. The L91 is a primary battery (single-use). It must never be placed in a charger (risk of explosion!). If you are looking for rechargeable batteries, choose NiMH rechargeable batteries (nickel-metal hydride).

Why does my measuring device show 1.8 volts?

Fresh Energizer lithium batteries have a very high open-circuit voltage of approx. 1.7 to 1.8 volts. This is normal and intentional. Almost all 1.5V devices can handle this voltage without any problems, as it quickly drops to a stable 1.5V - 1.6V under load. Only with extremely sensitive, old incandescent torch bulbs (without regulation) could the bulb blow, but this is very rare.

Is it better than a rechargeable battery (Eneloop)?

That depends.

• Advantage of Lithium L91: Higher voltage (1.5V vs 1.2V), no self-discharge (20-year shelf life), lighter, cold-resistant (-40°C). Better for: emergency use, smoke alarms, outdoor sensors, rarely used devices.
• Advantage of rechargeable battery (NiMH): Reusable, cheaper with frequent use. Better for: toys that are drained every day.

Why do I need it for my Blink camera?

Cameras like "Blink" communicate via WLAN and record video. This generates high current peaks (pulses). Alkaline batteries experience a voltage drop during these peaks (especially in cold weather), which the camera interprets as "battery empty", even though there would still be energy left. The L91 delivers the high current stably right to the end.