By Bryan Geyer
Re. “battery,” let’s nail the definition first. A single AA or AAA voltaic storage cell is actually not a “battery”; it’s a cell. A “battery” is a combination of two or more cells. So the sign at your local hardware store that directs you to the Energizer and Duracell AA and AAA “battery” display is technically in error. (That’s excusable, but the prices they post are not. You can do lots better at…https://www.batteryjunction.com.)
Yes, I realize that ramblings about AA and AAA (size) DC storage cells is distinctly outside my assigned specialty (audio nitty-gritty) here, but this is my 30th tech paper for this site, so host John Puccio (he of the chocolate digressions) has kindly allowed me some off-topic slack. The outcome of this liberty might well be more pertinent for you than anything in my previous 29 posts, so I say hey, listen up—this is stuff you need to know!
I’m an especially
heavy user of both AA and AAA voltaic storage cells. However, I have not
purchased any standard alkaline (LR6 class) AA or AAA cells since the late
1970s. Instead, I use only lithium (FR6 class) non-rechargeable AA and
AAA cells (aka L91 & L92 cells). I do so because these lithium iron disulfide
(LiFeS2) cells present a stack of compelling advantages over archaic alkaline
(manganese dioxide) cells, not the least of which is the fact that their
extended life generally makes them cost-competitive in all but a few benign
applications. The service life advantage of a lithium AA cell—when compared to
its alkaline equivalent—varies, dependent on how it will be utilized. In very
low drain service (e.g., a TV remote control) the lithium battery will outlast
an alkaline cell, but not by much. However, lithium longevity becomes
appreciable when used in higher drain service; e.g. in a flashlight or lantern,
or in photo strobes, RF transmitters, and in some portable audio equipment.
There’s a real 2X to 3X service life advantage, as compared to an alkaline
equivalent, in a great many common applications. For example, I’m seriously
into photo-macrography (close-ups) and also long lens wildlife photography
(mostly birds). These endeavors often involve using two or more electronic
strobes that can support rapid and repetitive high-power bursts, and the
related current drain is normally more than wimpy alkaline cells can sustain.
This is especially so in colder weather because alkaline cell output declines
rapidly when ambient temperatures approach +40˚F, whereas lithium AA or AAA
cells will still retain most of their native room-temp. punch.
While long service life is nice, maybe more important is the fact that lithium L91 AA cells will NEVER LEAK, even when discharged and left in your equipment for ≥ 5 years. (Been there, done that.) Conversely, all alkaline cells (of any brand) will eventually expel their noxious corrosive electrolyte (it’s KOH, potassium hydroxide) when they’re at or near a depleted state.
Further, lithium AA cells are ~ 40% lighter than alkaline equivalents, based on size AA comparison. That’s a helpful benefit, especially when you consider packing sufficient back-up spares.
The best place to buy Energizer non-rechargeable AA-size lithium (L91 type) cells is Battery Junction; see…https://www.batteryjunction.com/energizer-l91aa.html, where they’re $1.60 ea. + tax and shipping. The current Ace Hardware “walk in” price for Energizer Max alkaline AA cells (in an 8 pack) equates to $1.25 each + tax.
FR6-class lithium cells will retain ~ 94% of their capacity after 15+ years of storage, so it’s feasible to maintain extensive backup stock without concern. Alkaline cells degrade more rapidly. They’re specified to be storable for ~ 5 years if kept in cool dry environs, and then be down by only ~ 10%. However, I think that’s a rather idealistic projection.
The story is the same for AAA size cells. Energizer’s lithium (FR6 class) AAA cells are known as type L92, and their listing at Battery Junction is…https://www.batteryjunction.com/energizer-l92-bulk.html. The lithium cell benefits and characteristics that are noted above also apply for the smaller AAA (L92) size lithium cells.
Regarding Travel & Safety: The perilous warnings that you’ve heard about lithium battery fire hazards are real, but they trace entirely to the use of multi-cell rechargeable-type lithium-ion batteries, as commonly used today in cellular smart ’phones, digital cameras, and portable computers (also Teslas). A non-rechargeable (single use) L91/L92 type lithium (LiFeS2) cell does not pose the same fire threat. However, to assure that the federal safety mandate has clear and effective public compliance, ALL lithium power sources are now lumped as posing such fire hazard. As a consequence, you are not permitted to ship lithium cells without a related exterior warning sticker, and shipping by air (or by sea) is banned within the USA. Regardless, when you are traveling by commercial air service, you can then carry on equipment that utilizes lithium cells. This means that all of your battery-powered “carry on” gear (your cell ’phones, computers, digital cameras, strobes, flashlights, et al), whether using lithium cells or not, are welcome aboard the passenger compartment of the aircraft. Packing such devices in your checked luggage is permissible only if they are “…completely powered off and protected to prevent unintentional activation or damage.” This latter restriction is subject to the whim of the TSA agent on duty, so you’d best “carry on” your battery-operated devices. Further, all back-up stocks of uninstalled “…lithium metal and lithium ion batteries are always prohibited in checked baggage and must be placed in carry-on.” And: “When a carry-on bag is checked at the gate or at plane side, any spare lithium batteries must be removed from the bag and kept with the passenger in the aircraft cabin.” (On your person, not in your shoulder bag or briefcase.) Obviously, these last requirements don’t pertain to L91/L92 cells, but they directly apply to any backup rechargeable-type li-ion camera body batteries that you might have in your possession. The relevant TSA publication is here…https://www.faa.gov/hazmat/packsafe/more_info/?hazmat=20 (Issued 5/31/2018).
Re. NiMH Rechargeable Cells: In closing, please take note that many AA and AAA cell users rely on rechargeable nickel metal-hydride (NiMH) cells as their preferred alternate to alkaline cells. NiMH rechargeable storage cells work quite nicely for many applications (far, far better than the older nickel-cadmium rechargeable alternative), but the self-discharge rate for NiMH cells still makes them suspect for general usage. A fully charged NiMH cell reads about 1.2 Vdc when under load at the start (versus ~ 1.55 Vdc for a fresh alkaline cell), but it will sag to ~ 0.9 Vdc after just 6 to 8 weeks of passive storage. Conversely, a stock non-rechargeable L91 (AA) or L92 (AAA) lithium battery will read ~ 1.6 to 1.7 Vdc initially when under load regardless of whether it’s new or has been in storage for several years.
--BG (May 20, 2021)
Re. “battery,” let’s nail the definition first. A single AA or AAA voltaic storage cell is actually not a “battery”; it’s a cell. A “battery” is a combination of two or more cells. So the sign at your local hardware store that directs you to the Energizer and Duracell AA and AAA “battery” display is technically in error. (That’s excusable, but the prices they post are not. You can do lots better at…https://www.batteryjunction.com.)
Yes, I realize that ramblings about AA and AAA (size) DC storage cells is distinctly outside my assigned specialty (audio nitty-gritty) here, but this is my 30th tech paper for this site, so host John Puccio (he of the chocolate digressions) has kindly allowed me some off-topic slack. The outcome of this liberty might well be more pertinent for you than anything in my previous 29 posts, so I say hey, listen up—this is stuff you need to know!
While long service life is nice, maybe more important is the fact that lithium L91 AA cells will NEVER LEAK, even when discharged and left in your equipment for ≥ 5 years. (Been there, done that.) Conversely, all alkaline cells (of any brand) will eventually expel their noxious corrosive electrolyte (it’s KOH, potassium hydroxide) when they’re at or near a depleted state.
Further, lithium AA cells are ~ 40% lighter than alkaline equivalents, based on size AA comparison. That’s a helpful benefit, especially when you consider packing sufficient back-up spares.
The best place to buy Energizer non-rechargeable AA-size lithium (L91 type) cells is Battery Junction; see…https://www.batteryjunction.com/energizer-l91aa.html, where they’re $1.60 ea. + tax and shipping. The current Ace Hardware “walk in” price for Energizer Max alkaline AA cells (in an 8 pack) equates to $1.25 each + tax.
FR6-class lithium cells will retain ~ 94% of their capacity after 15+ years of storage, so it’s feasible to maintain extensive backup stock without concern. Alkaline cells degrade more rapidly. They’re specified to be storable for ~ 5 years if kept in cool dry environs, and then be down by only ~ 10%. However, I think that’s a rather idealistic projection.
The story is the same for AAA size cells. Energizer’s lithium (FR6 class) AAA cells are known as type L92, and their listing at Battery Junction is…https://www.batteryjunction.com/energizer-l92-bulk.html. The lithium cell benefits and characteristics that are noted above also apply for the smaller AAA (L92) size lithium cells.
Regarding Travel & Safety: The perilous warnings that you’ve heard about lithium battery fire hazards are real, but they trace entirely to the use of multi-cell rechargeable-type lithium-ion batteries, as commonly used today in cellular smart ’phones, digital cameras, and portable computers (also Teslas). A non-rechargeable (single use) L91/L92 type lithium (LiFeS2) cell does not pose the same fire threat. However, to assure that the federal safety mandate has clear and effective public compliance, ALL lithium power sources are now lumped as posing such fire hazard. As a consequence, you are not permitted to ship lithium cells without a related exterior warning sticker, and shipping by air (or by sea) is banned within the USA. Regardless, when you are traveling by commercial air service, you can then carry on equipment that utilizes lithium cells. This means that all of your battery-powered “carry on” gear (your cell ’phones, computers, digital cameras, strobes, flashlights, et al), whether using lithium cells or not, are welcome aboard the passenger compartment of the aircraft. Packing such devices in your checked luggage is permissible only if they are “…completely powered off and protected to prevent unintentional activation or damage.” This latter restriction is subject to the whim of the TSA agent on duty, so you’d best “carry on” your battery-operated devices. Further, all back-up stocks of uninstalled “…lithium metal and lithium ion batteries are always prohibited in checked baggage and must be placed in carry-on.” And: “When a carry-on bag is checked at the gate or at plane side, any spare lithium batteries must be removed from the bag and kept with the passenger in the aircraft cabin.” (On your person, not in your shoulder bag or briefcase.) Obviously, these last requirements don’t pertain to L91/L92 cells, but they directly apply to any backup rechargeable-type li-ion camera body batteries that you might have in your possession. The relevant TSA publication is here…https://www.faa.gov/hazmat/packsafe/more_info/?hazmat=20 (Issued 5/31/2018).
Re. NiMH Rechargeable Cells: In closing, please take note that many AA and AAA cell users rely on rechargeable nickel metal-hydride (NiMH) cells as their preferred alternate to alkaline cells. NiMH rechargeable storage cells work quite nicely for many applications (far, far better than the older nickel-cadmium rechargeable alternative), but the self-discharge rate for NiMH cells still makes them suspect for general usage. A fully charged NiMH cell reads about 1.2 Vdc when under load at the start (versus ~ 1.55 Vdc for a fresh alkaline cell), but it will sag to ~ 0.9 Vdc after just 6 to 8 weeks of passive storage. Conversely, a stock non-rechargeable L91 (AA) or L92 (AAA) lithium battery will read ~ 1.6 to 1.7 Vdc initially when under load regardless of whether it’s new or has been in storage for several years.
--BG (May 20, 2021)
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