I have five of these things:
https://www.amazon.com/Duracell-Dura...ews/B00NZTE97S

Three of them seem tb OK, but two drain the batteries: 2-3 months on the
shelf and the batteries are dead.

If it were all 5, I could buy the allegations of a flawed design.

But only 2? I'm thinking some sort of quality control issue.

Does anybody know enough about LED lights in general to ballpark the
problem? Not knowing anything, I tend to think it's the screw-on
switch/back of the light.
--
Pete Cresswell

On Fri, 26 May 2017 20:44:23 -0400, "(PeteCresswell)"
wrote:

I have five of these things:
https://www.amazon.com/Duracell-Dura...ews/B00NZTE97S

I see that you've been shopping at Costco:
https://www.amazon.com/Duracell-Durabeam-Tactical-High-Intensity-Flashlight/dp/B00NZTE97S
Junk but cheap. There's no reason you should be using alkaline
batteries for high power lighting when LiIon is so much better.

Hmmm.... 108 positive reviews and 255 critical reviews. That should
be a clue.

Three of them seem tb OK, but two drain the batteries: 2-3 months on the
shelf and the batteries are dead.
If it were all 5, I could buy the allegations of a flawed design.
But only 2? I'm thinking some sort of quality control issue.

Yep, that's a good possibility. Did you try to measure the current
drain when the flashlight was off? Just unscrew the battery cap and
attach a DVM ammeter with clipleads. My guess is you'll see a few
milliamps drain when off.

Does anybody know enough about LED lights in general to ballpark the
problem? Not knowing anything, I tend to think it's the screw-on
switch/back of the light.

That's possible. Inside the tail switch is the on/off, dimmer, and
flasher electronics. Here's a teardown of a similar model Duracell
1300 flashlight. I don't think repair is an option because it seems
impossible to disassemble without breaking something:
https://www.youtube.com/watch?v=cpERkuuFciw
Start at 6:00 for the tail switch.


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

On Fri, 26 May 2017 20:44:23 -0400, "(PeteCresswell)"
wrote:

I have five of these things:
https://www.amazon.com/Duracell-Dura...ews/B00NZTE97S

Three of them seem tb OK, but two drain the batteries: 2-3 months on the
shelf and the batteries are dead.

If it were all 5, I could buy the allegations of a flawed design.

But only 2? I'm thinking some sort of quality control issue.

Does anybody know enough about LED lights in general to ballpark the
problem? Not knowing anything, I tend to think it's the screw-on
switch/back of the light.

Someone once handed me one of those cheap $5 or less LED flashlights,
and said "What's wrong with this thing?". I took a look. When the switch
was turned ON, it worked fine and was bright. When the switch was turned
to the OFF position, the LEDs were still lit, but extremely dim.

I have to admit, I was puzzled. I ripped it apart as much as possible.
Icould not find any reason. I could only figure that there was some sort
of resistance leaking across that switch, but I did not have a
multimeter on hand. Plus the switch could not be removed without
destroying the flashlight.

I just told the owner to remove the batteries when they are not using
it.

On the other hand, I own at least a dozen of those (similar) cheap LED
flashlights sold by Walmart for $1. I have no complaints. They work
fine, and for the price they are worth buying. The only bad thing is
that it costs $1 (or more) to replace the three AAA batteries, so it's
ofter cheaper to just buy another flashlight (they come with batteries).

However, "Dollar Tree" has a 4 pack of AAA batts for $1, so that only
costs 75 cents for replacement batteries....

On Saturday, 27 May 2017 19:14:03 UTC+1, wrote:
On Fri, 26 May 2017 20:44:23 -0400, "(PeteCresswell)"
wrote:

I have five of these things:
https://www.amazon.com/Duracell-Dura...ews/B00NZTE97S

Three of them seem tb OK, but two drain the batteries: 2-3 months on the
shelf and the batteries are dead.

If it were all 5, I could buy the allegations of a flawed design.

But only 2? I'm thinking some sort of quality control issue.

Does anybody know enough about LED lights in general to ballpark the
problem? Not knowing anything, I tend to think it's the screw-on
switch/back of the light.

Someone once handed me one of those cheap $5 or less LED flashlights,
and said "What's wrong with this thing?". I took a look. When the switch
was turned ON, it worked fine and was bright. When the switch was turned
to the OFF position, the LEDs were still lit, but extremely dim.

I have to admit, I was puzzled. I ripped it apart as much as possible.
Icould not find any reason. I could only figure that there was some sort
of resistance leaking across that switch, but I did not have a
multimeter on hand. Plus the switch could not be removed without
destroying the flashlight.

I just told the owner to remove the batteries when they are not using
it.

On the other hand, I own at least a dozen of those (similar) cheap LED
flashlights sold by Walmart for $1. I have no complaints. They work
fine, and for the price they are worth buying. The only bad thing is
that it costs $1 (or more) to replace the three AAA batteries, so it's
ofter cheaper to just buy another flashlight (they come with batteries).

However, "Dollar Tree" has a 4 pack of AAA batts for $1, so that only
costs 75 cents for replacement batteries....

use rechargeables.


NT

Per :
use rechargeables.

I suspect that the issue for most people is dollars-and-cents battery
costs, but instead whether-or-not the light works when somebody grabs it
during a power failure or something after it's been on the shelf for 3
months.
--
Pete Cresswell

On Mon, 29 May 2017 17:54:14 -0400, "(PeteCresswell)"
wrote:

Per :
use rechargeables.

I suspect that the issue for most people is dollars-and-cents battery
costs, but instead whether-or-not the light works when somebody grabs it
during a power failure or something after it's been on the shelf for 3
months.

There's another issue, which is what inspired me to get away from
alkaline and switch to LiIon and NiMH. Just about every alkaline
battery brand that I've tried will leak and rot out the device it is
suppose to power. I just recycled yet another 2D Maglite flashlight.
At least once per month, I have clean out the guts from a 2way radio,
clock, weather station, etc from the crud oozing out of alkaline
cells. There must be a better way.

For devices that require AA and AAA cells, I'm using LSD (low self
discharge) NiMH cells, mostly Eneloop. I had to use a pair of FRS
radios last weekend which were last charged in Dec 2016. 6 months
later, the charge indicator showed about 80% charge and they ran the
radios all day. Good enough.
https://en.wikipedia.org/wiki/Eneloop#AA_size
See charge retention table.

For flashlights, I've almost finished switching to all LiIon
batteries, mostly 18650 and 14500.
http://802.11junk.com/jeffl/crud/LiIon%20Flashlights.jpg
That's about 1/3 of my growing collection of cheap LiIon batteries and
flashlights. Why so many? Because most of what arrives is a mixture
of not what I ordered, mechanical defects, premature electrical
failure, bad design, or bad construction. To insure that things will
go awry, I'm also buying nothing but the cheapest LiIon batteries at
$0.85/ea for 14500 to $1.30 for 18650. Why buy bottom of the line?
Because it's my contention that bottom of the line batteries are a
better deal on the basis of cost per energy delivered than buying
quality high capacity cells. It will take another 6 months or so to
be sure, but so far so good. Cheap 18650 battery capacity at 1.5A,
which is at the high end of what a flashlight will draw:
http://802.11junk.com/jeffl/battery-tests/18650.jpg

Drivel: There's even a web site for cheap flashlight enthusiasts:
http://budgetlightforum.com

The only fly in the flashlight ointment is the cost of a decent
battery charger. Most of the really cheap battery chargers are badly
designed, dangerous, or both. For example, this loser sells for about
$0.50 with many flashlight and battery combinations:
http://lygte-info.dk/review/Review%20Charger%20Bowei%20HC-103W%20UK.html
How customs even lets them into the country is a mystery.

Before you buy a charger, check he
http://www.lygte-info.dk/info/indexBatteriesAndChargers%20UK.html
Also avoid any dual battery charger with only one LED light. These
charge 2 batteries in parallel, which is a rather bad idea, but will
work for one battery at a time.

Real LiIon chargers are quite a bit more expensive. These are good so
far:
http://www.ebay.com/itm/301383587686 $10
http://www.ebay.com/itm/331572608015 $17.20

Bottom line is that you can get a decent bottom of the line flashlight
system for:
flashlight: $3 to $8
18650 battery: $1.50
Charger $10
==========================
Total $15 (approx)
Of course, the expensive charger can be used with multiple
flashlights, so the 2nd flashlight will cost only about $5.

For LiIon battery packs with multiple cells, I use a balance charger:
https://hobbyking.com/en_us/catalogsearch/result/?q=imax+b6
The charger is the most important and most expensive part of the
system. I built a 10watt LED light, that runs on 11.3VDC, which uses
a balance charger.

Oh yes, self discharge. Li-Ion is as good or better than LSD NiMH:
http://batteryuniversity.com/learn/article/elevating_self_discharge
See Tables 3 and 5. There's a rumor that storing a LiIon battery at
full charge would shorten its useful life. That was certainly a
problem with laptop batteries during the 1990's, but seems to have
been eliminated in the current offerings.

Anyway, think rechargeable, recycle your alkalines, and return the
flashlights to Costco.

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

On 5/29/2017 4:43 PM, Jeff Liebermann wrote:
On Mon, 29 May 2017 17:54:14 -0400, "(PeteCresswell)"
wrote:

Per :
use rechargeables.

I suspect that the issue for most people is dollars-and-cents battery
costs, but instead whether-or-not the light works when somebody grabs it
during a power failure or something after it's been on the shelf for 3
months.

There's another issue, which is what inspired me to get away from
alkaline and switch to LiIon and NiMH. Just about every alkaline
battery brand that I've tried will leak and rot out the device it is
suppose to power. I just recycled yet another 2D Maglite flashlight.
At least once per month, I have clean out the guts from a 2way radio,
clock, weather station, etc from the crud oozing out of alkaline
cells. There must be a better way.

I'd agree, but many of my devices won't run on that voltage.
Wireless power monitors and thermometers, for example.

For devices that require AA and AAA cells, I'm using LSD (low self
discharge) NiMH cells, mostly Eneloop. I had to use a pair of FRS
radios last weekend which were last charged in Dec 2016. 6 months
later, the charge indicator showed about 80% charge and they ran the
radios all day. Good enough.
https://en.wikipedia.org/wiki/Eneloop#AA_size
See charge retention table.

For flashlights, I've almost finished switching to all LiIon
batteries, mostly 18650 and 14500.

What's your experience with 14500 in single AA flashlights?
Mine get hot enough with NiMH. I'm afraid to run them on 4V
at 7W.
Here's an example:
http://www.everbuying.net/product867812.html

http://802.11junk.com/jeffl/crud/LiIon%20Flashlights.jpg
That's about 1/3 of my growing collection of cheap LiIon batteries and
flashlights. Why so many? Because most of what arrives is a mixture
of not what I ordered, mechanical defects, premature electrical
failure, bad design, or bad construction. To insure that things will
go awry, I'm also buying nothing but the cheapest LiIon batteries at
$0.85/ea for 14500 to $1.30 for 18650. Why buy bottom of the line?
Because it's my contention that bottom of the line batteries are a
better deal on the basis of cost per energy delivered than buying
quality high capacity cells. It will take another 6 months or so to
be sure, but so far so good. Cheap 18650 battery capacity at 1.5A,
which is at the high end of what a flashlight will draw:
http://802.11junk.com/jeffl/battery-tests/18650.jpg

Lowes has a six-cell 18650 lithium tool battery for $10.
Only 1.5AH, but rated for 30 Amps max.
Was gonna replace NiCd in an old drill, but I'm procrastinating.



Drivel: There's even a web site for cheap flashlight enthusiasts:
http://budgetlightforum.com

The only fly in the flashlight ointment is the cost of a decent
battery charger. Most of the really cheap battery chargers are badly
designed, dangerous, or both. For example, this loser sells for about
$0.50 with many flashlight and battery combinations:
http://lygte-info.dk/review/Review%20Charger%20Bowei%20HC-103W%20UK.html
How customs even lets them into the country is a mystery.

I have one that looks identical except has US plug.
Terminates just fine below 4.2V. Doesn't seem to have any of the
characteristics shown in the review.
I didn't take mine apart.

Before you buy a charger, check he
http://www.lygte-info.dk/info/indexBatteriesAndChargers%20UK.html
Also avoid any dual battery charger with only one LED light. These
charge 2 batteries in parallel, which is a rather bad idea, but will
work for one battery at a time.

Real LiIon chargers are quite a bit more expensive. These are good so
far:
http://www.ebay.com/itm/301383587686 $10
http://www.ebay.com/itm/331572608015 $17.20

Bottom line is that you can get a decent bottom of the line flashlight
system for:
flashlight: $3 to $8
18650 battery: $1.50
Charger $10
==========================
Total $15 (approx)
Of course, the expensive charger can be used with multiple
flashlights, so the 2nd flashlight will cost only about $5.

For LiIon battery packs with multiple cells, I use a balance charger:
https://hobbyking.com/en_us/catalogsearch/result/?q=imax+b6
The charger is the most important and most expensive part of the
system. I built a 10watt LED light, that runs on 11.3VDC, which uses
a balance charger.

Oh yes, self discharge. Li-Ion is as good or better than LSD NiMH:
http://batteryuniversity.com/learn/article/elevating_self_discharge
See Tables 3 and 5. There's a rumor that storing a LiIon battery at
full charge would shorten its useful life. That was certainly a
problem with laptop batteries during the 1990's, but seems to have
been eliminated in the current offerings.

Anyway, think rechargeable, recycle your alkalines, and return the
flashlights to Costco.

On 30/05/17 12:57, Jeff Liebermann wrote:
On Mon, 29 May 2017 18:10:06 -0700, mike wrote:
I'd agree, but many of my devices won't run on that voltage.
Wireless power monitors and thermometers, for example.
Most everything that will run on alkaline cells will also run on LSD
NiMH cells.

However, you can't just plug in a LiIon cell into a device made for
alkaline cells, even if they fit. For example, if you try to replace
a common AA alkaline cell with a 14500 LiIon cell, you are replacing a
1.5V cell with a 3.6V cell, which will likely burn out the device.
However, you may be able to replace two AA alkaline cells with a
single LiIon cell if device will tolerate a 20% increase in battery
voltage.

They even sell blank AA cells (containing a wire from +ve to -ve)
for devices that can use one Li cell instead of two alkalines.
I use these in an Apple Bluetooth keyboard for example.

What's your experience with 14500 in single AA flashlights?
The Cree XP-E Q5 LED is designed to operate at about 350ma and will
generate about 120 lumens depending on type and bin selection:
http://www.cree.com/led-components/media/documents/XLampXPE-25A.pdf
That's about:
120 lm / (3.6v * 0.35A) = 95 lumens/watt
which is consistent with todays LEDs at room temp. There is no way
the XP-E Q5 LED will dissipate 7 watts or produce 600+ lumens.

Except in Chinese marketing materials

Lowes has a six-cell 18650 lithium tool battery for $10.
Only 1.5AH, but rated for 30 Amps max.
Was gonna replace NiCd in an old drill, but I'm procrastinating.

It depends on which tool and how the conversion is done.

I did this with my Ryobi, and use it every day:
http://polyplex.org/electronics/ryobi_lifepo4/index.html
It used to have 11 stubby NiCD cells, now four 26550 LiIons.
Recently reworked with a female balance connector, after it
short circuited in a toolbox and burnt one of the wires.

If you plan to do this, make sure
you use a LiIon/LiPo/whatever charger.

Hobbyking supplied a Turnigy Accucel-6 for $25, which runs nicely
off an old laptop power brick.

Clifford Heath.

On Mon, 29 May 2017 18:10:06 -0700, mike wrote:

I'd agree, but many of my devices won't run on that voltage.
Wireless power monitors and thermometers, for example.

Most everything that will run on alkaline cells will also run on LSD
NiMH cells.

However, you can't just plug in a LiIon cell into a device made for
alkaline cells, even if they fit. For example, if you try to replace
a common AA alkaline cell with a 14500 LiIon cell, you are replacing a
1.5V cell with a 3.6V cell, which will likely burn out the device.
However, you may be able to replace two AA alkaline cells with a
single LiIon cell if device will tolerate a 20% increase in battery
voltage. Most devices that have a voltage regulator will work nicely.
Those without voltage regulators, will overheat.

What's your experience with 14500 in single AA flashlights?
Mine get hot enough with NiMH. I'm afraid to run them on 4V
at 7W.
Here's an example:
http://www.everbuying.net/product867812.html

I don't understand. 14500 is the size of a AA cell which applies to
alkaline, NiMH, and LiIon, LIPO, LiFePO4, etc, all of which have
different terminal voltages. The flashlight appears to be designed
for a 14500 size NiMH battery. Running it on a AA alkaline will kill
the battery in short order because it can't handle the current.
Running it on an LiIon battery will blow it up because it will be over
twice the rated voltage. There's no information on the above web site
as to whether the light is intended to operate on alkaline, NiMH, or
LiIon voltages, but a comment by a user indicating that "7 days on a
single AA Enelope" suggests NiMH. Do NOT install a LiIon 14500 cell
as it will probably burn out the electronics (also known as the
"pill").

The Cree XP-E Q5 LED is designed to operate at about 350ma and will
generate about 120 lumens depending on type and bin selection:
http://www.cree.com/led-components/media/documents/XLampXPE-25A.pdf
That's about:
120 lm / (3.6v * 0.35A) = 95 lumens/watt
which is consistent with todays LEDs at room temp. There is no way
the XP-E Q5 LED will dissipate 7 watts or produce 600+ lumens.

In order to run on a single 1.35V nominal NiMH cell, the flashlight
will require a boost converter and a current regulator. Done
correctly, these work just fine. Done badly, they get hot and burn
up. My guess(tm) is that this flashlight is in the latter category.

Lowes has a six-cell 18650 lithium tool battery for $10.
Only 1.5AH, but rated for 30 Amps max.
Was gonna replace NiCd in an old drill, but I'm procrastinating.

It depends on which tool and how the conversion is done. I have
several Makita 9.6v nominal power tools, that were intended to run on
NiCd or NiMH, now converted to run on 11.3v (3 cells) LiIon cells. I
was concerned about the increase in voltage, so I added a series power
diode to drop the voltage. Works fine but admittedly does get warm
when run heavily. Many LiIon (LiPo) battery packs can be discharged
at 10C or more (that's 10 times the rated current in Amp-Hrs). That
sets the minimum cell size to 18650, where my junk cells test at about
1000ma-hr capacity at 1.5A. 14500 would be to small. For charging,
the recommended charge rate is 1C. If you plan to do this, make sure
you use a LiIon/LiPo/whatever charger. I should mention that cramming
18650 cells into some battery packs is a major project. The good part
is that such conversions require fewer cells. You might also consider
using prismatic cells such as:
https://hobbyking.com/en_us/turnigy-1000mah-1s-20c-lipoly-single-cell.html
Make sure you leave room to let them inflate when charging.

For example, this loser sells for about
$0.50 with many flashlight and battery combinations:
http://lygte-info.dk/review/Review%20Charger%20Bowei%20HC-103W%20UK.html
How customs even lets them into the country is a mystery.

I have one that looks identical except has US plug.

Spray a little water into the charger and then measure the AC voltage
between an electrical neutral wire and either battery terminal. The
life you save may be your own. I stupidly bought 10 of these before I
realized what a POS they were. I destroyed them before recycling so
that nobody would get hurt.

Terminates just fine below 4.2V. Doesn't seem to have any of the
characteristics shown in the review.
I didn't take mine apart.

I measured one of mine. When it got to 4.25V, I stopped to prevent
destroying the battery.

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

On Tue, 30 May 2017 12:42:03 +1000, Clifford Heath
wrote:

What's your experience with 14500 in single AA flashlights?

The Cree XP-E Q5 LED is designed to operate at about 350ma and will
generate about 120 lumens depending on type and bin selection:
http://www.cree.com/led-components/media/documents/XLampXPE-25A.pdf
That's about:
120 lm / (3.6v * 0.35A) = 95 lumens/watt
which is consistent with todays LEDs at room temp. There is no way
the XP-E Q5 LED will dissipate 7 watts or produce 600+ lumens.

Except in Chinese marketing materials

There are a few simple sanity checks for lumen claims. Unfortunately,
they have to be done after you've spent the money.

1. Measure the current drain with an ammeter. Assume that initial
lumens/watt luminous efficacy is about 75 lm/watt for consumer
lighting including some loss through the optics. So, if your
flashlight draws 1.0A at 3.6V, your flashlight will produce
approximately:
1.0A * 3.6v * 75 lm/watt = 263 lumens
You can also look up the specs for the LED, but that doesn't always
work because some lights claim to have the latest greatest high
efficiency LED, but actually use bin fallout, rejects, or
counterfeits.

2. Buy a cheap lux meter on eBay such as:
http://www.ebay.com/itm/381903904643
There are better models, but this one seems to track measurements with
my other more expensive meters quite well. Hang it on the wall and
project a round spot on the wall with the flashlight. Measure and
record the spot diameter and lux values.
1 Lux = 1 lumen/sq-meter
Calculate the area of the spot in square meters. Multiply the
measured lux value by the area and you have lumens. Notice that you
do NOT need to record the distance between the flashlight and the
meter.

Problem. The spot is not uniform brightness across its diameter. To
compensate, I like to measure the hot spot at the center, half way
between the center and the edge, and near the edge. I then calculate
(or guess) an average lux value.

No integrating sphere or tube required.

If you want to make calculations easy, a 1 square meter circle has a
diameter of 1.13 meters (44.5 in). Mark this on the wall and move the
flashlight back and forth until the edges of the spot hits the marks.
The lux meter will then read directly in lumens.

This measurement becomes difficult when measuring odd shaped spots,
such as with bicycle and automotive headlights, but I won't go there.


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

On Monday, 29 May 2017 22:54:20 UTC+1, (PeteCresswell) wrote:
Per tabbypurr

use rechargeables.

I suspect that the issue for most people is dollars-and-cents battery
costs, but instead whether-or-not the light works when somebody grabs it
during a power failure or something after it's been on the shelf for 3
months.

Even cheapie rechargeable NiMH do that no problem IME, and are less likely to corrode the contacts. There might be some out there that don't, but I think that issue has been exaggerated.


NT

Per Jeff Liebermann:
rechargeables...

That one was a keeper: thanks.

Is your reason for using LiIon in flashlights the near-zero
self-discharge?

I have been using Eneloops, but not in all of my lights.... yet.
--
Pete Cresswell

On Tue, 30 May 2017 09:18:23 -0400, "(PeteCresswell)"
wrote:

Is your reason for using LiIon in flashlights the near-zero
self-discharge?

No. It's my total disgust with the damage done by leaking alkalines.
I discovered something new with the last alkaline battery leak. Even
though the battery leaks had made a big mess inside the flashlight, it
still lit up normally. So, turning on the light to see if it is still
alive is NOT a substitute for visual inspection. Argh.

My main reason for getting into flashlights is that I'm bored and
wanted to play with some different toys. I've been reading Candle
Power Forums for quite a while and thought flashlights might be fun.
The major incentive was a non-monetary bet with a friend over the
usefulness of bottom of the line LiIon cells. My contention is that
they are economically justifiable, while he demands nothing but the
best.

Another reason I won't trust alkalines. They die in the box:
http://802.11junk.com/jeffl/crud/Kirkland-AAA-leak.jpg

I just remembered that I'm suppose to fix an Apple BlueGoof wireless
keyboard. The alkaline batteries leaked and the stainless steel screw
on cover, into an aluminum housing, it rotted shut. I've tried brute
force, with no effect. Chemical attack comes next.

I have been using Eneloops, but not in all of my lights.... yet.

Same here, but I prefer LiIon. I've been having problems with
ordinary NiMH. In addition to self discharge, they don't seem to last
through too many charge cycles. Typically, I get about 200 with NiMH
and 1200 or more with NiCd. Overall, I do better with NiCd for
something that requires regular recharging, such as handheld radios,
and flashlights. I'm doing something wrong with NiMH, but haven't
figured out what.

Also, LiIon has a much higher maximum discharge current. 20C is
common while NiMH is maybe 5C. It's the higher energy density of
LiIon that has made power hogs like quadcopters and high power
flashlights possible. They could be made to work on NiMH, but
performance would suffer. LiIon has also force the introduction of
decent battery chargers. One can get away with crude and simple with
NiCd and NiMH, but not with LiIon. LiIon requires a well designed
charger. Multiple cells charged in series require a balance charger.
Many NiCd and NiMH chargers will merrily kill batteries with "quick
charge" and various memory effect cures, but even a mediocre LiIon
charger will do a reasonable job without killing the cells. Of
course, there are plenty of ways to do it wrong, but so far, that's
been the exception, not the rule.



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

On Tuesday, 30 May 2017 17:24:01 UTC+1, Jeff Liebermann wrote:

Same here, but I prefer LiIon. I've been having problems with
ordinary NiMH. In addition to self discharge, they don't seem to last
through too many charge cycles. Typically, I get about 200 with NiMH
and 1200 or more with NiCd. Overall, I do better with NiCd for
something that requires regular recharging, such as handheld radios,
and flashlights. I'm doing something wrong with NiMH, but haven't
figured out what.

Discharging too far is their biggest killer. Or to put it another way, mismatched cells. When one flattens the others push current through it & it suffers badly.


NT

I purchased a 3 pack of the model 350 at Costco. Everyone one of them has this issue. 3 months is about right. Put new batteries in all of them and a few months later they all are virtually drained of battery life.

Matt C

On Mon, 20 May 2019 15:18:29 -0700, dmatthew.carter wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of them
has this issue. 3 months is about right. Put new batteries in all of
them and a few months later they all are virtually drained of battery
life.
Well, of COURSE! The purpose of selling a flashlight is to sell
BATTERIES! If you can design the flashlight to DRAIN the batteries, then
you sell more batteries! What a brilliant concept.

Does this thing have an electronic circuit to turn the light on and off?
Maybe that circuit has some small current to keep it operating.

Jon

On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C

That would be a Duracell Durabeam Ultra 350. The current version sold
by Costco is the Durabeam Ultra 380, which is the same flashlight
package except all 3 flashlights are black. I would guess(tm) that
the 350 was last sold in early 2017, so you probably bought "old
stock" that was sitting on the shelf for about 2 years.
https://costco97.com/duracell-led-flashlights-3-pack/

A unique feature of these Duracell line of flashlights (350, 380, 500)
is that they use FOUR alkaline cells instead of the usual three. This
is an attempt to squeeze more lumens out of the flashlight at the
expense of battery life. The driver (current regulator) chip used may
have been originally designed to run at 3.0 to 4.0v for one LiIon, and
maybe 3.9 to 4.8v for three alkaline cells, but might have problems
with 5.2 to 6.4v for four alkaline cells. My guess(tm) is that these
lights used the usual AMC7135 current regulator IC which is rated at
350ma from 2.7 to 6.0v.
https://www.electroschematics.com/wp-content/uploads/2016/04/acm7135-datasheet.pdf
In my limited experience tinkering with some of these chips, I found
that 6.0v really is the absolute maximum voltage that can be used and
that some (not all) chips will blow up at around 7v. Running these on
4 alkaline cells seems a bit close for comfort. Unfortunately, I did
not check for leakage current through the driver. It's easy enough to
do. Install 4 brand new alkaline cells and measure the current drain
when off. If you measure any leakage current, you can guesstimate the
standby life of the battery by dividing the capacity of a single cell
by this current. For example, if you measured 0.1ma of leakage, all
four AAA cells will be depleted in:
750ma-hr / 0.1ma = 7,500 hrs
which equals:
7,500hrs / 24 hrs/day = 313 days
or about 1 year. Based upon your 3 month experience, and that the
package was probably sitting on the shelf for a while, I would
guess(tm) you should see about 0.35ma of leakage.

However, all is not lost. There are LiIon inserts made to fit in
place of alkaline battery holder. This is commonly done with
flashlights that take 3 alkaline cells:
https://www.youtube.com/watch?v=yNo_k_LOWMM
It can also be done with an 18500 LiIon cell, if you can find one.
I've done much the same thing except I used a hard rubber chemistry
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.

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

On Mon, 20 May 2019 18:56:59 -0700, Jeff Liebermann
wrote:

My guess(tm) is that these
lights used the usual AMC7135 current regulator IC which is rated at
350ma from 2.7 to 6.0v.
https://www.electroschematics.com/wp-content/uploads/2016/04/acm7135-datasheet.pdf

Duh. Maybe I should have looked at the data sheet before I continued
to guess. See graph on Pg3 "QUIESCENT CURRENT vs. SUPPLY VOLTAGE".
The graph only goes to 4.1v which is a subtle hint that 6v might be a
bad idea. They could have used two or three AMC7135 chips in parallel
to obtain the necessary current handling, but then the leakage current
would be 2x or 3x as high. Killing the batteries with this leakage
current in 3 months is quite possible.

However, much depends on whether the Duracell Durabeam Ultra 350 uses
an AMC7135, and whether power is always applied to the AMC7135. I
can't tell from here without disassembling the flashlight, reverse
engineering the schematic, and making a few measurements.

Deconstructing a flashlight:
https://kandepet.com/deconstructing-a-flashlight/

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

On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote:
On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C

....
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.

or use NiMH


NT

I think NiMH is 1.2V while cells are 1.5V.

a écrit le 21/05/2019 Ã* 11:01Â*:
On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote:
On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C
...
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.
or use NiMH


NT

On Tue, 21 May 2019 02:01:46 -0700 (PDT), wrote:

On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote:
On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C

...
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.

or use NiMH
NT

Yep, that will work better than alkaline. 800ma-hr for NiMH instead
of 750ma-hr for alkaline. The actual difference will be larger
because NiMH tolerates high current loads better than alkaline.

I'm partial to LSD (low self discharge) NiMH cells. About $2.50/cell
from China:
https://www.ebay.com/itm/400827732093
or $4.00/cell from USA vendor:
https://www.ebay.com/itm/153458804452
Four cells per flashlight would cost $10 to $16 per flashlight. For
that price, I could buy an equivalent LiIon flashlight, and still have
some money left over for a crude LiIon charger. Most of these:
http://www.learnbydestroying.com/jeffl/crud/LiIon%20Flashlights.jpg
were $5 to $10/ea plus charger.

I forgot to mumble something about the leakage current. Because the
on-off switch is usually in series with the battery, the "off" leakage
current should be zero. Yet, the Duracell Durabeam Ultra 350
flashlights seem to be leaking some current. Therefore, my guess(tm)
is that the flashlight is wired in a somewhat different manner. Since
the purpose of this flashlight is to sell more AAA batteries, I
wouldn't put it past Duracell to put something across the switch or
use a different wiring configuration to produce some leakage current.


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

On 5/20/2019 3:18 PM, wrote:
I purchased a 3 pack of the model 350 at Costco. Everyone one of them has this issue. 3 months is about right. Put new batteries in all of them and a few months later they all are virtually drained of battery life.

Matt C

This is a common problem with the electronic switching.

google flashlight parasitic drain

A flashlight that's dead when you need it is worthless.
Take 'em back to Costco.

Newer flashlights advertise "no parasitic drain".
Get one that explicitly states that. Anything else is a crap shoot.

On Saturday, May 27, 2017 at 11:46:35 AM UTC-7, wrote:
On Saturday, 27 May 2017 19:14:03 UTC+1, wrote:

However, "Dollar Tree" has a 4 pack of AAA batts for $1, so that only
costs 75 cents for replacement batteries....

use rechargeables.

Only viable if you have a charger that takes three cells (or charges one-at-a-time).
Many chargers only charge pairs. Usually (squint at the fine print)
'1.5V' means it'll work on onesies, twosies, threesies, foursies.
"2.8V' on my Energizer charger means it only works on two or four.

On Tuesday, 21 May 2019 10:36:56 UTC+1, Look165 wrote:
tabbypurr a écrit le 21/05/2019 Ã* 11:01Â*:
On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote:
On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C
...
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.

or use NiMH


NT

I think NiMH is 1.2V while cells are 1.5V.

Alkaline start at 1.55v ad are totally flat at about 0.8v. NiMH stay at about 1.2v for most of their discharge.


NT

On Tuesday, 21 May 2019 17:29:22 UTC+1, Jeff Liebermann wrote:
On Tue, 21 May 2019 02:01:46 -0700 (PDT), tabbypurr wrote:
On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote:
On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C

...
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.

or use NiMH
NT

Yep, that will work better than alkaline. 800ma-hr for NiMH instead
of 750ma-hr for alkaline. The actual difference will be larger
because NiMH tolerates high current loads better than alkaline.

I'm partial to LSD (low self discharge) NiMH cells. About $2.50/cell
from China:
https://www.ebay.com/itm/400827732093
or $4.00/cell from USA vendor:
https://www.ebay.com/itm/153458804452
Four cells per flashlight would cost $10 to $16 per flashlight. For
that price, I could buy an equivalent LiIon flashlight, and still have
some money left over for a crude LiIon charger. Most of these:
http://www.learnbydestroying.com/jeffl/crud/LiIon%20Flashlights.jpg
were $5 to $10/ea plus charger.

So the choice of $2.50/ cells was not a good one. Try 50 cent cells.

I forgot to mumble something about the leakage current. Because the
on-off switch is usually in series with the battery, the "off" leakage
current should be zero. Yet, the Duracell Durabeam Ultra 350
flashlights seem to be leaking some current. Therefore, my guess(tm)
is that the flashlight is wired in a somewhat different manner. Since
the purpose of this flashlight is to sell more AAA batteries, I
wouldn't put it past Duracell to put something across the switch or
use a different wiring configuration to produce some leakage current.

that may be a reason to go new.


NT

On Wednesday, 22 May 2019 07:48:10 UTC+1, whit3rd wrote:
On Saturday, May 27, 2017 at 11:46:35 AM UTC-7, tabby wrote:
On Saturday, 27 May 2017 19:14:03 UTC+1, wrote:

However, "Dollar Tree" has a 4 pack of AAA batts for $1, so that only
costs 75 cents for replacement batteries....

use rechargeables.

Only viable if you have a charger that takes three cells (or charges one-at-a-time).
Many chargers only charge pairs. Usually (squint at the fine print)
'1.5V' means it'll work on onesies, twosies, threesies, foursies.
"2.8V' on my Energizer charger means it only works on two or four.

I assumed we'd all be able to charge 3 cells. Maybe not so.


NT

On Wed, 22 May 2019 04:52:09 -0700 (PDT), wrote:

So the choice of $2.50/ cells was not a good one. Try 50 cent cells.

The cheap NiMH cells have a high self-discharge rate. They are quite
suitable for some applications, such as devices that are left almost
permanently in a charger, such as home cordless phones, some power
tools, but area a giant pain for devices that are left off for long
periods of time, such as flashlights, cameras, test equipment, etc.
Before LSD NiMH cells, I still recall practicing my profanity when I
had to charge a device before I used it. No thanks.

https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery#Self-discharge
The self-discharge is 5-20% on the first day and stabilizes
around 0.5-4% per day at room temperature. But at 45 °C it
is approximately three times as high.

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

On Wednesday, 22 May 2019 15:45:05 UTC+1, Jeff Liebermann wrote:
On Wed, 22 May 2019 04:52:09 -0700 (PDT), tabbypurr wrote:

So the choice of $2.50/ cells was not a good one. Try 50 cent cells.

The cheap NiMH cells have a high self-discharge rate. They are quite
suitable for some applications, such as devices that are left almost
permanently in a charger, such as home cordless phones, some power
tools, but area a giant pain for devices that are left off for long
periods of time, such as flashlights, cameras, test equipment, etc.
Before LSD NiMH cells, I still recall practicing my profanity when I
had to charge a device before I used it. No thanks.

https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery#Self-discharge
The self-discharge is 5-20% on the first day and stabilizes
around 0.5-4% per day at room temperature. But at 45 °C it
is approximately three times as high.

I've heard that said a lot, but it doesn't match my experience. Fusiomax have usually still had lots of charge in them months later. I have a drawer of various NiCd & NiMH, random ones I wouldn't have as much confidence in. IIRC you can get cheaper deals from China than the fusios.

In the 90s I used a gas powered torch. No battery torch comes anywhere near it in reliability terms.


NT

On 5/22/2019 4:52 AM, wrote:
On Tuesday, 21 May 2019 17:29:22 UTC+1, Jeff Liebermann wrote:
On Tue, 21 May 2019 02:01:46 -0700 (PDT), tabbypurr wrote:
On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote:
On Mon, 20 May 2019 15:18:29 -0700 (PDT),
wrote:

I purchased a 3 pack of the model 350 at Costco. Everyone one of
them has this issue. 3 months is about right. Put new batteries
in all of them and a few months later they all are virtually
drained of battery life.
Matt C

...
cork instead of a wine bottle cork. However, I haven't seen anything
for doing it with 4 alkaline cells. That's probably a waste of time,
so I suggest you recycle the flashlight and buy something that runs on
a LiIon cell and not on alkaline cells.

or use NiMH
NT

Yep, that will work better than alkaline. 800ma-hr for NiMH instead
of 750ma-hr for alkaline. The actual difference will be larger
because NiMH tolerates high current loads better than alkaline.

I'm partial to LSD (low self discharge) NiMH cells. About $2.50/cell
from China:
https://www.ebay.com/itm/400827732093
or $4.00/cell from USA vendor:
https://www.ebay.com/itm/153458804452
Four cells per flashlight would cost $10 to $16 per flashlight. For
that price, I could buy an equivalent LiIon flashlight, and still have
some money left over for a crude LiIon charger. Most of these:
http://www.learnbydestroying.com/jeffl/crud/LiIon%20Flashlights.jpg
were $5 to $10/ea plus charger.

So the choice of $2.50/ cells was not a good one. Try 50 cent cells.

I forgot to mumble something about the leakage current. Because the
on-off switch is usually in series with the battery, the "off" leakage
current should be zero. Yet, the Duracell Durabeam Ultra 350
flashlights seem to be leaking some current. Therefore, my guess(tm)
is that the flashlight is wired in a somewhat different manner. Since
the purpose of this flashlight is to sell more AAA batteries, I
wouldn't put it past Duracell to put something across the switch or
use a different wiring configuration to produce some leakage current.

that may be a reason to go new.


NT

Conspiracy theory notwithstanding...

I suggest that some designer made a bad decision to use a cheap
part to manage the flashlight modes. Some manager made an uninformed
decision to remarket the result. Everybody saved a penny, except the user.
Caught with their pants down, some vendors are now advertising flashlights
with zero parasitic drain.
It's unlikely that Duracell had any malicious intent in this.

There really is no clean fix for this. If you use your flashlight every
day, it won't affect you much. If you use it infrequently for emergencies,
you absolutely, positively want it to work when needed.
About all you can do is put an insulator somewhere in the battery
assembly and remove it when the emergency happens.

Next time, buy one that advertises zero parasitic drain.

On Wed, 22 May 2019 17:52:10 -0700, Mike wrote:

Conspiracy theory notwithstanding...

I just hate it when someone ruins a perfectly good conspiracy theory.
Never attribute to malice that which is adequately explained
by stupidity. Hanlon's Razor.

Standby/parasitic current drain of various flashlights (including
leakage current and estimated battery life):
https://lygte-info.dk/info/standbyCurrent%20UK.html

I suggest that some designer made a bad decision to use a cheap
part to manage the flashlight modes. Some manager made an uninformed
decision to remarket the result. Everybody saved a penny, except the user.
Caught with their pants down, some vendors are now advertising flashlights
with zero parasitic drain.
It's unlikely that Duracell had any malicious intent in this.

There is already a class action suit to prove otherwise:

"Duracell Class Action Says LED Flashlights Drain Batteries Quickly"
https://topclassactions.com/lawsuit-settlements/consumer-products/877506-duracell-class-action-says-led-flashlights-drain-batteries-quickly/
https://www.classaction.org/blog/in-the-dark-allegedly-defective-duracell-led-flashlights-drain-batteries-when-turned-off-class-action-lawsuit-claims
https://www.classaction.org/media/siddle-et-al-v-the-duracell-company-et-al.pdf
(12.4MB)
The case seeks to cover a proposed nationwide class of
consumers who bought Duracell’s 250, 300 or 350 LED
flashlight models from Duracell, Costco, Home Depot or
Amazon during the to-be-defined claim period.

There really is no clean fix for this. If you use your flashlight every
day, it won't affect you much. If you use it infrequently for emergencies,
you absolutely, positively want it to work when needed.
About all you can do is put an insulator somewhere in the battery
assembly and remove it when the emergency happens.

With alkaline cells, I like to store them outside of the device in a
plastic bag. I've had too many problems with alkaline cells leaking
all over the inside of flashlights, radios, and toys.

Next time, buy one that advertises zero parasitic drain.

Probably a good idea. I guess I've been lucky as none of mine seem to
have the problem. However, I haven't measured it, so I'm not really
sure.


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

On 5/22/2019 7:26 PM, Jeff Liebermann wrote:
On Wed, 22 May 2019 17:52:10 -0700, Mike wrote:

Conspiracy theory notwithstanding...

I just hate it when someone ruins a perfectly good conspiracy theory.
Never attribute to malice that which is adequately explained
by stupidity. Hanlon's Razor.

Standby/parasitic current drain of various flashlights (including
leakage current and estimated battery life):
https://lygte-info.dk/info/standbyCurrent%20UK.html

I suggest that some designer made a bad decision to use a cheap
part to manage the flashlight modes. Some manager made an uninformed
decision to remarket the result. Everybody saved a penny, except the user.
Caught with their pants down, some vendors are now advertising flashlights
with zero parasitic drain.
It's unlikely that Duracell had any malicious intent in this.

There is already a class action suit to prove otherwise:

"Duracell Class Action Says LED Flashlights Drain Batteries Quickly"
https://topclassactions.com/lawsuit-settlements/consumer-products/877506-duracell-class-action-says-led-flashlights-drain-batteries-quickly/
https://www.classaction.org/blog/in-the-dark-allegedly-defective-duracell-led-flashlights-drain-batteries-when-turned-off-class-action-lawsuit-claims
https://www.classaction.org/media/siddle-et-al-v-the-duracell-company-et-al.pdf
(12.4MB)
The case seeks to cover a proposed nationwide class of
consumers who bought Duracells 250, 300 or 350 LED
flashlight models from Duracell, Costco, Home Depot or
Amazon during the to-be-defined claim period.

You can sue anybody for anything. Sometimes you even win.
BUT
I don't expect anybody at Duracell ever sat down with the evil
intent to sell defective flashlights as a means to increase battery sales.
It's much more likely that someone in purchasing decided they could
make a buck on flashlights and did zero evaluation.

I skimmed part of the attached links.

Should they be punished for not recalling them? Probably, but what
is the appropriate punishment? We all have stuff that performs
less than expected. Where do you draw the line?

I'd bet that Costco took back any presented for refund.
Don't know about the others.

The people with flashlights ain't gonna get rich, but the lawyers sure
will get rich off this lawsuit.

I have several of these that I bought at garage sales. Didn't take long
to discover why they were almost free. I probably won't be able to make
a claim without a receipt. Stick a piece of plastic between the battery
pack and the spring.
They'll be fine when needed in an emergency.
Another strategy is to leave batteries in the flashlight, wait for
them to leak, get reimbursed for leaky batteries.

If I were to sue Duracell, it would be over leaky batteries that ruin
the devices they power. I'd get behind serious punishment for that.
Although I've had them replace seriously damaged devices on demand.

It's all about the Benjamins. If replacement cost is less than the
additional profit, that's what controls the decision. In this case,
they ****ed off the wrong ambulance chasers. ;-)

There really is no clean fix for this. If you use your flashlight every
day, it won't affect you much. If you use it infrequently for emergencies,
you absolutely, positively want it to work when needed.
About all you can do is put an insulator somewhere in the battery
assembly and remove it when the emergency happens.

With alkaline cells, I like to store them outside of the device in a
plastic bag. I've had too many problems with alkaline cells leaking
all over the inside of flashlights, radios, and toys.

Next time, buy one that advertises zero parasitic drain.

Probably a good idea. I guess I've been lucky as none of mine seem to
have the problem. However, I haven't measured it, so I'm not really
sure.

On Thursday, 23 May 2019 09:33:33 UTC+1, Mike wrote:
On 5/22/2019 7:26 PM, Jeff Liebermann wrote:
On Wed, 22 May 2019 17:52:10 -0700, Mike wrote:

Conspiracy theory notwithstanding...

I just hate it when someone ruins a perfectly good conspiracy theory.
Never attribute to malice that which is adequately explained
by stupidity. Hanlon's Razor.

Standby/parasitic current drain of various flashlights (including
leakage current and estimated battery life):
https://lygte-info.dk/info/standbyCurrent%20UK.html

I suggest that some designer made a bad decision to use a cheap
part to manage the flashlight modes. Some manager made an uninformed
decision to remarket the result. Everybody saved a penny, except the user.
Caught with their pants down, some vendors are now advertising flashlights
with zero parasitic drain.
It's unlikely that Duracell had any malicious intent in this.

There is already a class action suit to prove otherwise:

"Duracell Class Action Says LED Flashlights Drain Batteries Quickly"
https://topclassactions.com/lawsuit-settlements/consumer-products/877506-duracell-class-action-says-led-flashlights-drain-batteries-quickly/
https://www.classaction.org/blog/in-the-dark-allegedly-defective-duracell-led-flashlights-drain-batteries-when-turned-off-class-action-lawsuit-claims
https://www.classaction.org/media/siddle-et-al-v-the-duracell-company-et-al.pdf
(12.4MB)
The case seeks to cover a proposed nationwide class of
consumers who bought Duracells 250, 300 or 350 LED
flashlight models from Duracell, Costco, Home Depot or
Amazon during the to-be-defined claim period.

You can sue anybody for anything. Sometimes you even win.
BUT
I don't expect anybody at Duracell ever sat down with the evil
intent to sell defective flashlights as a means to increase battery sales..

Usually companies are busy looking for the next wheeze, the next way to sell more product. And we surely know that a lot of these ideas are knowingly not in the consumer's interest.

It's much more likely that someone in purchasing decided they could
make a buck on flashlights and did zero evaluation.

a company that size with a large reputation doing zero evaluation? Not credible

I skimmed part of the attached links.

Should they be punished for not recalling them? Probably, but what
is the appropriate punishment? We all have stuff that performs
less than expected. Where do you draw the line?

afaik parasitic drain is not a crime. I don't know any law that prohibits it.