Energizer · Premium
Energizer Ultimate Lithium AA (model L91) is a 1.5V lithium AA cell that Energizer specifies for use from -40°F to 140°F and for up to 25 years in storage, offered here as an eight-battery pack.
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We have not tested it ourselves: strengths and weaknesses below come from the tests cited.
Railfans spend long stretches standing beside the tracks, and winter is when the gear suffers. Energizer lists a working range of -40°F to 140°F (-40°C to 60°C) for this battery, while its own comparison chart gives its standard alkaline AA a range of 0°F to 130°F. If a camera or other AA-powered device is left out in the cold during a long wait for a train, that wider written range is the reason to carry lithium cells. Energizer also says these batteries weigh one-third less than standard alkaline cells, and its chart gives 0.5 oz per AA against 0.8 oz for the alkaline, which counts when you carry spares in a bag all day.
Energizer names digital cameras and game controllers as high-tech uses, along with smoke detectors, toys and games, and its comparison chart lists digital cameras, digital audio and home automation among the devices it suggests for this battery. For trackside work, that makes it a spare-cell option for any gear that takes AA cells: check your device manual to confirm which chemistries it accepts before you buy. The 25-year storage figure means a spare set can stay in a camera bag or a glovebox between seasons; Energizer gives its standard alkaline AA up to 12 years on the same chart. Energizer describes the construction as leak resistant and states the batteries are leak proof based on standard use, which matters for equipment you do not open for months. This is a primary battery: Energizer's own chart classes it with alkaline cells that have a finite life and need to be replaced, so keep a spare set rather than expecting to recharge.
Strengths
Weaknesses
| Specification | Value |
|---|---|
| Size | AA (FR6) |
| Weight | 0.5 oz per AA (15 g for the L91 cell in the test summary) |
| Voltage | 1.5V |
| Chemistry | Lithium iron disulfide (lithium metal) |
| Shelf life | Up to 25 years |
| Leak protection | Leak resistant construction; leak proof based on standard use |
| Lithium content | Less than 1 g per cell |
| Recycled content | Steel up to 10% recycled |
| Temperature range | -40°F to 140°F (-40°C to 60°C) |
A railfan who photographs or monitors in cold weather and wants spare AA cells with a written working range down to -40°F. It also suits anyone who stores spare batteries for long periods, given the 25-year storage figure. It does not suit someone who wants to recharge cells and reuse them, because this is a primary battery. Confirm that your device accepts lithium AA cells first.
Energizer MAX AA is the manufacturer's alkaline option: its chart gives it 0°F to 130°F use, 0.8 oz per AA and up to 12 years of storage, so it covers milder weather with a heavier cell. Energizer Recharge AA (NiMH) is the choice for reuse, rated by the maker at up to 1,000 charge cycles in one version and up to 500 in another.
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