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Guest

Tue Feb 12, 2019 7:45 am   



On Tuesday, February 12, 2019 at 1:30:08 AM UTC-5, Mike wrote:
Quote:
On 2/11/2019 7:06 PM, Jeff Liebermann wrote:
On Mon, 11 Feb 2019 18:58:58 -0800, Jeff Liebermann <jeffl_at_cruzio.com
wrote:

Nope. I've asked and checked the web pile. No alkaline 9V batteries.
What they do have is a "heavy duty" 9V battery, which means carbon
zinc. No thanks.
https://www.dollartree.com/bulk/9-Volt-Battery

Worse. While the local store still has Sunbeam 4 AAA cells for $1,
the web pile is now offering only 3 AAA cells per package.
https://www.dollartree.com/search/go?w=&w=alkaline+battery
Probably time to stock up on some 4 AAA per packages.

Also, the offering of 2 AAA and 2 AA cells per package with "34% more
power" makes me wonder if the 4 AAA per cell devices are in some way
inferior. When I find the time, maybe some discharge testing will
help.

Their coin cells, CR2032 etc., have recently switched from 2/1$ to 1$ each.


I order coin cells off eBay and get maybe 10/$1. At that price it's affordable to keep them on hand just in case they are needed.

I bought some CR2354 cells just in case my key dies. They are monsters for coin cells!

Rick C.

Jeff Liebermann
Guest

Wed Feb 13, 2019 1:45 am   



On Mon, 11 Feb 2019 22:33:16 -0500, krw_at_notreal.com wrote:

Quote:
If you leave batteries in the appliance and care about it, invest in
LiFeS2 cells, generally used for cameras and flash units. Energizer
sells AA and AAA sized "L92s" (E92s are the common alkalines).


<https://www.energizer.com/batteries/energizer-ultimate-lithium-batteries>
Good idea as the prices for AA and AAA cells has dropped to under
$1/ea in small quantities:
<https://www.google.com/search?tbm=shop&q=energizer+L92>
I probably would do that except that I prefer rechargeable cells to
throw away cells. For direct replacement, NiMH LSD (Eneloop) are
about $3/ea. L92 AA are 3000 ma-hr, while Eneloop AA are 2500 ma-hr.
Break even is about 5 recharge cycles, after which NiMH becomes less
expensive.

>I don't believe they make 9V batteries in the LiFeS2 chemistry, though.

Energizer Ultimate L522-BP-2 at two for $19.
<https://www.energizer.com/batteries/energizer-ultimate-lithium-batteries#9v>
<http://data.energizer.com/pdfs/l522.pdf>
Hmmm... These seem to be a different chemistry.
Lithium-Manganese Dioxide (Li/MnO2).
Visually interpolating from the graphs, I would guess about 550 ma-hr
discharge down to 7.0V (a more reasonable voltage than 5.4V). Anyway,
at $8.50/ea, they're far too expensive.

Incidentally, I wrap my alkaline 9V batteries in cellophane wrap or
absorbent paper covered with cellophane wrap to restrict the leaking
electrolyte to only destroying the battery and not the instrument. It
doesn't always work perfectly, but does minimize the damage.

Quote:
They're about a buck a piece from Amazon but they're worth it. They
have a shelf life of something like 20 years and will take heat better
than alkalines. Great for emergency flashlights.


If it's a real emergency flashlight, I suggest that you reconsider
your suggestion. We have no way of knowing the SoC (state of charge)
of the battery in storage. It could have been borrowed my some
unknown person and returned to its storage location. When again
needed, it would have a shorter than expected runtime. I can buy SoC
meters for LiIon that measure the terminal voltage, but I haven't seen
one for LiFeS2. It would be easy enough to produce a family of curves
at various operating temperatures, but so far, nobody seems to have
done it. So, for my emergency lighting, I use rechargeable cells that
can be individually characterized, charged, and tested for SoC.


--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


Guest

Wed Feb 13, 2019 4:45 am   



On Tue, 12 Feb 2019 16:41:16 -0800, Jeff Liebermann <jeffl_at_cruzio.com>
wrote:

Quote:
On Mon, 11 Feb 2019 22:33:16 -0500, krw_at_notreal.com wrote:

If you leave batteries in the appliance and care about it, invest in
LiFeS2 cells, generally used for cameras and flash units. Energizer
sells AA and AAA sized "L92s" (E92s are the common alkalines).

https://www.energizer.com/batteries/energizer-ultimate-lithium-batteries
Good idea as the prices for AA and AAA cells has dropped to under
$1/ea in small quantities:
https://www.google.com/search?tbm=shop&q=energizer+L92
I probably would do that except that I prefer rechargeable cells to
throw away cells. For direct replacement, NiMH LSD (Eneloop) are
about $3/ea. L92 AA are 3000 ma-hr, while Eneloop AA are 2500 ma-hr.
Break even is about 5 recharge cycles, after which NiMH becomes less
expensive.


NiMH has too high of a self-discharge for my likes. I want the widget
to work when I need it. NiMH work well for my wife's solar garden
lights, though. They're dirt cheap and good enough for cycling every
day.
Quote:

I don't believe they make 9V batteries in the LiFeS2 chemistry, though.

Energizer Ultimate L522-BP-2 at two for $19.
https://www.energizer.com/batteries/energizer-ultimate-lithium-batteries#9v
http://data.energizer.com/pdfs/l522.pdf
Hmmm... These seem to be a different chemistry.
Lithium-Manganese Dioxide (Li/MnO2).


Yes. Different chemistry.

Quote:
Visually interpolating from the graphs, I would guess about 550 ma-hr
discharge down to 7.0V (a more reasonable voltage than 5.4V). Anyway,
at $8.50/ea, they're far too expensive.

Incidentally, I wrap my alkaline 9V batteries in cellophane wrap or
absorbent paper covered with cellophane wrap to restrict the leaking
electrolyte to only destroying the battery and not the instrument. It
doesn't always work perfectly, but does minimize the damage.


If it's worth doing that, it's worth buying a better battery.
Quote:

They're about a buck a piece from Amazon but they're worth it. They
have a shelf life of something like 20 years and will take heat better
than alkalines. Great for emergency flashlights.

If it's a real emergency flashlight, I suggest that you reconsider
your suggestion. We have no way of knowing the SoC (state of charge)
of the battery in storage. It could have been borrowed my some
unknown person and returned to its storage location. When again
needed, it would have a shorter than expected runtime. I can buy SoC
meters for LiIon that measure the terminal voltage, but I haven't seen
one for LiFeS2. It would be easy enough to produce a family of curves
at various operating temperatures, but so far, nobody seems to have
done it. So, for my emergency lighting, I use rechargeable cells that
can be individually characterized, charged, and tested for SoC.


There are only two of us in the house an only one drives each vehicle.

LiFeS2 cells have an incredibly flat discharge curve. A SoC meter
would be pretty tough to do, I would guess.

Jeff Liebermann
Guest

Wed Feb 13, 2019 4:45 am   



On Tue, 12 Feb 2019 21:52:47 -0500, krw_at_notreal.com wrote:

Quote:
On Tue, 12 Feb 2019 16:41:16 -0800, Jeff Liebermann <jeffl_at_cruzio.com
wrote:

On Mon, 11 Feb 2019 22:33:16 -0500, krw_at_notreal.com wrote:

If you leave batteries in the appliance and care about it, invest in
LiFeS2 cells, generally used for cameras and flash units. Energizer
sells AA and AAA sized "L92s" (E92s are the common alkalines).

https://www.energizer.com/batteries/energizer-ultimate-lithium-batteries
Good idea as the prices for AA and AAA cells has dropped to under
$1/ea in small quantities:
https://www.google.com/search?tbm=shop&q=energizer+L92
I probably would do that except that I prefer rechargeable cells to
throw away cells. For direct replacement, NiMH LSD (Eneloop) are
about $3/ea. L92 AA are 3000 ma-hr, while Eneloop AA are 2500 ma-hr.
Break even is about 5 recharge cycles, after which NiMH becomes less
expensive.

NiMH has too high of a self-discharge for my likes. I want the widget
to work when I need it. NiMH work well for my wife's solar garden
lights, though. They're dirt cheap and good enough for cycling every
day.


I beg to differ. The self discharge rate of Eneloop NiMH LSD (low
self discharge) cells is quite acceptable. I charged some Panasonic
AA cells, stuffed them in my DSLR camera, and let it sit unused for
about 9 months. After 9 months, they had something like 90% of full
charge available. Different generations have different self discharge
rates. See table at:
<https://en.wikipedia.org/wiki/Eneloop#AA_size>

Quote:
LiFeS2 cells have an incredibly flat discharge curve. A SoC meter
would be pretty tough to do, I would guess.


From almost full to dead is about a 200mv range. Expanded, it doesn't
look all that flat. Linearized (with a lookup table) that's 2mv = 1%
change in SoC. Not idea of cheap BMS systems, but certainly doable.
Attach a good voltmeter, make sure the terminal connections aren't
corroded, and you have a tolerable SoC meter. To avoid customer
confusion, make the display rather grainy with 5 steps of 20% each:
<https://batteryuniversity.com/_img/content/exam2.jpg>

--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


Guest

Wed Feb 13, 2019 5:45 am   



On Tue, 12 Feb 2019 19:38:57 -0800, Jeff Liebermann <jeffl_at_cruzio.com>
wrote:

Quote:
On Tue, 12 Feb 2019 21:52:47 -0500, krw_at_notreal.com wrote:

On Tue, 12 Feb 2019 16:41:16 -0800, Jeff Liebermann <jeffl_at_cruzio.com
wrote:

On Mon, 11 Feb 2019 22:33:16 -0500, krw_at_notreal.com wrote:

If you leave batteries in the appliance and care about it, invest in
LiFeS2 cells, generally used for cameras and flash units. Energizer
sells AA and AAA sized "L92s" (E92s are the common alkalines).

https://www.energizer.com/batteries/energizer-ultimate-lithium-batteries
Good idea as the prices for AA and AAA cells has dropped to under
$1/ea in small quantities:
https://www.google.com/search?tbm=shop&q=energizer+L92
I probably would do that except that I prefer rechargeable cells to
throw away cells. For direct replacement, NiMH LSD (Eneloop) are
about $3/ea. L92 AA are 3000 ma-hr, while Eneloop AA are 2500 ma-hr.
Break even is about 5 recharge cycles, after which NiMH becomes less
expensive.

NiMH has too high of a self-discharge for my likes. I want the widget
to work when I need it. NiMH work well for my wife's solar garden
lights, though. They're dirt cheap and good enough for cycling every
day.

I beg to differ. The self discharge rate of Eneloop NiMH LSD (low
self discharge) cells is quite acceptable. I charged some Panasonic
AA cells, stuffed them in my DSLR camera, and let it sit unused for
about 9 months. After 9 months, they had something like 90% of full
charge available. Different generations have different self discharge
rates. See table at:
https://en.wikipedia.org/wiki/Eneloop#AA_size


Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.

Quote:

LiFeS2 cells have an incredibly flat discharge curve. A SoC meter
would be pretty tough to do, I would guess.

From almost full to dead is about a 200mv range. Expanded, it doesn't
look all that flat. Linearized (with a lookup table) that's 2mv = 1%
change in SoC. Not idea of cheap BMS systems, but certainly doable.
Attach a good voltmeter, make sure the terminal connections aren't
corroded, and you have a tolerable SoC meter. To avoid customer
confusion, make the display rather grainy with 5 steps of 20% each:
https://batteryuniversity.com/_img/content/exam2.jpg


Jeff Liebermann
Guest

Thu Feb 14, 2019 6:45 am   



On Tue, 12 Feb 2019 22:46:50 -0500, krw_at_notreal.com wrote:

Quote:
Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.


Where did you find that number? I've been Googling for 15 minutes and
not been able to find any self discharge specs or tests. This is as
close as I could find, and it too doesn't specify down to what charge
level the cell was tested (usually 80% of full charge):

<https://en.wikipedia.org/wiki/Lithium_battery#Chemistries>
The section on LiFeS2 says:
"Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium,
because it can work as a replacement for alkaline batteries
with its 1.5 V nominal voltage. As such, Energizer lithium
cells of AA and AAA size employ this chemistry. 2.5 times
higher lifetime for high current discharge regime than
alkaline batteries, better storage life due to lower
self-discharge, 10-20 years storage time. FeS2 is cheap.
Cathode often designed as a paste of iron sulfide powder
mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:
<http://data.energizer.com/pdfs/lithiuml91l92_appman.pdf>

What does Elevated Self-discharge Do?
<https://batteryuniversity.com/learn/article/elevating_self_discharge>
Note that abusing LiIon cells by deep discharge and shorting the
terminals increases self discharge.


--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Mike
Guest

Thu Feb 14, 2019 7:45 am   



On 2/13/2019 8:48 PM, Jeff Liebermann wrote:
Quote:
On Tue, 12 Feb 2019 22:46:50 -0500, krw_at_notreal.com wrote:

Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.

Where did you find that number? I've been Googling for 15 minutes and
not been able to find any self discharge specs or tests. This is as
close as I could find, and it too doesn't specify down to what charge
level the cell was tested (usually 80% of full charge):

https://en.wikipedia.org/wiki/Lithium_battery#Chemistries
The section on LiFeS2 says:
"Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium,
because it can work as a replacement for alkaline batteries
with its 1.5 V nominal voltage. As such, Energizer lithium
cells of AA and AAA size employ this chemistry. 2.5 times
higher lifetime for high current discharge regime than
alkaline batteries, better storage life due to lower
self-discharge, 10-20 years storage time. FeS2 is cheap.
Cathode often designed as a paste of iron sulfide powder
mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:
http://data.energizer.com/pdfs/lithiuml91l92_appman.pdf

What does Elevated Self-discharge Do?
https://batteryuniversity.com/learn/article/elevating_self_discharge
Note that abusing LiIon cells by deep discharge and shorting the
terminals increases self discharge.


I can't cite a reference, but I read it on the internet, so it must be true.
Standard alkaline batteries have a stated shelf-life if you never put a
load on them.
Once presented with a load, further shelf life can decrease dramatically.

Jeff Liebermann
Guest

Thu Feb 14, 2019 7:45 pm   



On Wed, 13 Feb 2019 22:31:46 -0800, Mike <ham789_at_netscape.net> wrote:

Quote:
On 2/13/2019 8:48 PM, Jeff Liebermann wrote:
On Tue, 12 Feb 2019 22:46:50 -0500, krw_at_notreal.com wrote:

Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.

Where did you find that number? I've been Googling for 15 minutes and
not been able to find any self discharge specs or tests. This is as
close as I could find, and it too doesn't specify down to what charge
level the cell was tested (usually 80% of full charge):

https://en.wikipedia.org/wiki/Lithium_battery#Chemistries
The section on LiFeS2 says:
"Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium,
because it can work as a replacement for alkaline batteries
with its 1.5 V nominal voltage. As such, Energizer lithium
cells of AA and AAA size employ this chemistry. 2.5 times
higher lifetime for high current discharge regime than
alkaline batteries, better storage life due to lower
self-discharge, 10-20 years storage time. FeS2 is cheap.
Cathode often designed as a paste of iron sulfide powder
mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:
http://data.energizer.com/pdfs/lithiuml91l92_appman.pdf

What does Elevated Self-discharge Do?
https://batteryuniversity.com/learn/article/elevating_self_discharge
Note that abusing LiIon cells by deep discharge and shorting the
terminals increases self discharge.

I can't cite a reference, but I read it on the internet, so it must be true.


Everyone lies. But, that's ok because nobody listens.
My usual excuse is that I can't offer a reference because I'm too busy
or lazy to Google for one.

Quote:
Standard alkaline batteries have a stated shelf-life if you never put a
load on them.


"Mercury in Batteries"
<https://www.epa.gov/mercury/mercury-batteries>
Prior to about 1996, alkaline batteries contained a small amount of
mercury. That's what kept alkalines and others from leaking by
outgassing. At about the same time, the expiration time (shelf life)
was shortened for alkalines. Where to find the date:
<https://www.medicbatteries.com/alkaline-battery-life-aa-battery-life-9v-battery-life>
This is different from self discharge rate as some of the leaky
batteries that I've tested seemed to be just fine. (I should have run
a discharge test on some for verification). For example, I had an
incandescent flashlight that had leaky D size Duracell alkaline cells,
that was quite bright for about 30 minutes.

Also, some of these worked fairly normally, even though they leaked:
<http://www.learnbydestroying.com/jeffl/crud/Kirkland-AAA-leak.jpg>

>Once presented with a load, further shelf life can decrease dramatically.

Agreed. A battery that is never used will theoretically last forever.



--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


Guest

Fri Feb 15, 2019 4:45 am   



On Wed, 13 Feb 2019 22:31:46 -0800, Mike <ham789_at_netscape.net> wrote:

Quote:
On 2/13/2019 8:48 PM, Jeff Liebermann wrote:
On Tue, 12 Feb 2019 22:46:50 -0500, krw_at_notreal.com wrote:

Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.

Where did you find that number? I've been Googling for 15 minutes and
not been able to find any self discharge specs or tests. This is as
close as I could find, and it too doesn't specify down to what charge
level the cell was tested (usually 80% of full charge):

https://en.wikipedia.org/wiki/Lithium_battery#Chemistries
The section on LiFeS2 says:
"Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium,
because it can work as a replacement for alkaline batteries
with its 1.5 V nominal voltage. As such, Energizer lithium
cells of AA and AAA size employ this chemistry. 2.5 times
higher lifetime for high current discharge regime than
alkaline batteries, better storage life due to lower
self-discharge, 10-20 years storage time. FeS2 is cheap.
Cathode often designed as a paste of iron sulfide powder
mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:
http://data.energizer.com/pdfs/lithiuml91l92_appman.pdf

What does Elevated Self-discharge Do?
https://batteryuniversity.com/learn/article/elevating_self_discharge
Note that abusing LiIon cells by deep discharge and shorting the
terminals increases self discharge.


I can't cite a reference, but I read it on the internet, so it must be true.
Standard alkaline batteries have a stated shelf-life if you never put a
load on them.
Once presented with a load, further shelf life can decrease dramatically.


That's my experience, as well. Whenever I use one of my "emergency"
flashlights, I pitch the batteries and put in fresh ones.


Guest

Fri Feb 15, 2019 4:45 am   



On Wed, 13 Feb 2019 20:48:45 -0800, Jeff Liebermann <jeffl_at_cruzio.com>
wrote:

Quote:
On Tue, 12 Feb 2019 22:46:50 -0500, krw_at_notreal.com wrote:

Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.

Where did you find that number? I've been Googling for 15 minutes and
not been able to find any self discharge specs or tests. This is as
close as I could find, and it too doesn't specify down to what charge
level the cell was tested (usually 80% of full charge):


The Energizer L92 datasheet, IIRC. I don't have it at home, though.
Quote:

https://en.wikipedia.org/wiki/Lithium_battery#Chemistries
The section on LiFeS2 says:
"Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium,
because it can work as a replacement for alkaline batteries
with its 1.5 V nominal voltage. As such, Energizer lithium
cells of AA and AAA size employ this chemistry. 2.5 times
higher lifetime for high current discharge regime than
alkaline batteries, better storage life due to lower
self-discharge, 10-20 years storage time. FeS2 is cheap.
Cathode often designed as a paste of iron sulfide powder
mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:
http://data.energizer.com/pdfs/lithiuml91l92_appman.pdf


That's not a datasheet. It's a product blurb, maybe.
Quote:

What does Elevated Self-discharge Do?
https://batteryuniversity.com/learn/article/elevating_self_discharge
Note that abusing LiIon cells by deep discharge and shorting the
terminals increases self discharge.


Not surprising but LiFeS2 <> LiIon.


Guest

Fri Feb 15, 2019 8:45 am   



On Friday, February 15, 2019 at 4:59:29 AM UTC+11, Jeff Liebermann wrote:
Quote:
On Wed, 13 Feb 2019 22:31:46 -0800, Mike <ham789_at_netscape.net> wrote:

On 2/13/2019 8:48 PM, Jeff Liebermann wrote:
On Tue, 12 Feb 2019 22:46:50 -0500, krw_at_notreal.com wrote:

Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.

Where did you find that number? I've been Googling for 15 minutes and
not been able to find any self discharge specs or tests. This is as
close as I could find, and it too doesn't specify down to what charge
level the cell was tested (usually 80% of full charge):

https://en.wikipedia.org/wiki/Lithium_battery#Chemistries
The section on LiFeS2 says:
"Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium,
because it can work as a replacement for alkaline batteries
with its 1.5 V nominal voltage. As such, Energizer lithium
cells of AA and AAA size employ this chemistry. 2.5 times
higher lifetime for high current discharge regime than
alkaline batteries, better storage life due to lower
self-discharge, 10-20 years storage time. FeS2 is cheap.
Cathode often designed as a paste of iron sulfide powder
mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:
http://data.energizer.com/pdfs/lithiuml91l92_appman.pdf

What does Elevated Self-discharge Do?
https://batteryuniversity.com/learn/article/elevating_self_discharge
Note that abusing LiIon cells by deep discharge and shorting the
terminals increases self discharge.

I can't cite a reference, but I read it on the internet, so it must be true.

Everyone lies. But, that's ok because nobody listens.
My usual excuse is that I can't offer a reference because I'm too busy
or lazy to Google for one.

Standard alkaline batteries have a stated shelf-life if you never put a
load on them.

"Mercury in Batteries"
https://www.epa.gov/mercury/mercury-batteries
Prior to about 1996, alkaline batteries contained a small amount of
mercury. That's what kept alkalines and others from leaking by
outgassing. At about the same time, the expiration time (shelf life)
was shortened for alkalines. Where to find the date:
https://www.medicbatteries.com/alkaline-battery-life-aa-battery-life-9v-battery-life
This is different from self discharge rate as some of the leaky
batteries that I've tested seemed to be just fine. (I should have run
a discharge test on some for verification). For example, I had an
incandescent flashlight that had leaky D size Duracell alkaline cells,
that was quite bright for about 30 minutes.

Also, some of these worked fairly normally, even though they leaked:
http://www.learnbydestroying.com/jeffl/crud/Kirkland-AAA-leak.jpg

Once presented with a load, further shelf life can decrease dramatically.

Agreed. A battery that is never used will theoretically last forever.


Not according to any theory I'm aware of. There's inevitably some way for stuff to diffuse around and decrease the stock of stored energy.

Some lithium cells are touted as having a twenty year shelf life (if stored below 20C), and the lithium coin cell that powers my watch does roughly seven year under load.

--
Bill Sloman, Sydney

Jeff Liebermann
Guest

Fri Feb 15, 2019 6:45 pm   



On Fri, 15 Feb 2019 09:15:56 -0800, Jeff Liebermann <jeffl_at_cruzio.com>
wrote:
Quote:
Sorry. I missed the real datasheet on my initial search. This should
be it for L92 AAA
http://data.energizer.com/pdfs/l92.pdf
and L91 AA.
http://data.energizer.com/pdfs/l91.pdf
They both say:
Shelf Life: 20 years at 21C
but don't bother to specify the conditions when the battery is
considered no longer suitable for sale or use. My guess(tm) is 80% of
full charge, but I haven't found that stated in any of the Energizer
literature.


Incidentally, the shelf life for an Energizer L91 AA *alkaline* cell
is claimed at 10 years @21C:
<http://data.energizer.com/pdfs/e91.pdf>
None of the alkaline cells I've bought have lasted that long and
usually leak in the box or in the instrument long before 10 years has
passed.

--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann
Guest

Fri Feb 15, 2019 6:45 pm   



On Thu, 14 Feb 2019 22:06:45 -0500, krw_at_notreal.com wrote:

Quote:
On Wed, 13 Feb 2019 20:48:45 -0800, Jeff Liebermann <jeffl_at_cruzio.com
wrote:

On Tue, 12 Feb 2019 22:46:50 -0500, krw_at_notreal.com wrote:

Self discharge for the Energizer LiFeS2 batteries is 20 years. Top
that with *any* Ni chemistry.

Where did you find that number? I've been Googling for 15 minutes and
not been able to find any self discharge specs or tests. This is as
close as I could find, and it too doesn't specify down to what charge
level the cell was tested (usually 80% of full charge):

The Energizer L92 datasheet, IIRC. I don't have it at home, though.

https://en.wikipedia.org/wiki/Lithium_battery#Chemistries
The section on LiFeS2 says:
"Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium,
because it can work as a replacement for alkaline batteries
with its 1.5 V nominal voltage. As such, Energizer lithium
cells of AA and AAA size employ this chemistry. 2.5 times
higher lifetime for high current discharge regime than
alkaline batteries, better storage life due to lower
self-discharge, 10-20 years storage time. FeS2 is cheap.
Cathode often designed as a paste of iron sulfide powder
mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:
http://data.energizer.com/pdfs/lithiuml91l92_appman.pdf

That's not a datasheet. It's a product blurb, maybe.


Sorry. I missed the real datasheet on my initial search. This should
be it for L92 AAA
<http://data.energizer.com/pdfs/l92.pdf>
and L91 AA.
<http://data.energizer.com/pdfs/l91.pdf>
They both say:
Shelf Life: 20 years at 21C
but don't bother to specify the conditions when the battery is
considered no longer suitable for sale or use. My guess(tm) is 80% of
full charge, but I haven't found that stated in any of the Energizer
literature.

--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann
Guest

Fri Feb 15, 2019 6:45 pm   



On Thu, 14 Feb 2019 22:07:49 -0500, krw_at_notreal.com wrote:

Quote:
That's my experience, as well. Whenever I use one of my "emergency"
flashlights, I pitch the batteries and put in fresh ones.


Polluter. What do you do when someone else uses one of your
"emergency" flashlights, and doesn't tell you that they used it? Do
you just assume that it will work when needed? With mission critical
hardware, such as UPS (uninterruptible power supply) batteries, the
batteries are replaced by a regular schedule, regardless of whether
they were used or not. That's how I sometimes get big UPS batteries
with about 50% of the life left in the batteries for free. Sometimes,
it includes the UPS. If you persist in using non-rechargeable
batteries, what you should be doing is buying a new "emergency"
flashlight every 6 months or so, and donating the old flashlight to
suitable charity. That should save you the trouble of recharging
batteries on a regular schedule, monitoring capacity, or measuring the
SoC (state of charge).

--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann
Guest

Fri Feb 15, 2019 6:45 pm   



On Thu, 14 Feb 2019 23:23:04 -0800 (PST), bill.sloman_at_ieee.org wrote:

Quote:
On Friday, February 15, 2019 at 4:59:29 AM UTC+11, Jeff Liebermann wrote:
On Wed, 13 Feb 2019 22:31:46 -0800, Mike <ham789_at_netscape.net> wrote:
Once presented with a load, further shelf life can decrease dramatically.

Agreed. A battery that is never used will theoretically last forever.

Not according to any theory I'm aware of. There's inevitably some way
for stuff to diffuse around and decrease the stock of stored energy.


If a tree falls in a forest and no one is around to hear it, does it
make a sound?
<https://en.wikipedia.org/wiki/If_a_tree_falls_in_a_forest>
The unused battery is much the same. If nobody uses or test the
battery, how does one know if it's charged or dead?

Quote:
Some lithium cells are touted as having a twenty year shelf life (if stored
below 20C), and the lithium coin cell that powers my watch does roughly
seven year under load.


Lithium thionyl chloride (LiSOCl2). They're up to 40 years now:
<http://www.tadiranbat.com>
<http://www.tadiranbat.com/is-a-40-year-battery-life-a-reality.html>
The major technology improvements come various ways to reduce self
discharge. If progress continues at the present rate of improvement,
we may eventually have a battery that will last longer than an average
human lifetime.


--
Jeff Liebermann jeffl_at_cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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