"Ultimate Lithium" vs Alkaline AAA in single cell LED flashlight

colab

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I've found an Energizer Ultimate Lithium AAA cell's output voltage drops to an unusable state after a few minutes use and takes many hours to recover, whereas a regular alkaline battery seems to work fine in my single AAA cell LED flashlight.

I have a single-AAA cell Fenix LD01 I keep clipped to my pocket for the last three years. Having an EDC light like that has proven to be fantastic. It's so small and light I don't notice it, and yet provides up to 80 lumens whenever I need it, and it's always there. The light has proven to be rugged, the clip has worked very well (only failed once in three years), and I like how it can be squeezed on, or twist to stay on.

The problem I've had is I thought I was smart to load it with Energizer Ultimate Lithium batteries. I've only ever used these batteries. Because it only takes one, the higher cost is still quite reasonable. I wanted the cold weather performance, which is vital on winter nights. I was led to believe they might last longer too. Although I use my light perhaps a half-dozen to a dozen times a week, I usually only need a for a few seconds at a time. A single AAA lasts several months or more before I change it, often proactively to ensure it doesn't die at the wrong time.

However, I've found that if I use the light for several minutes and turn it off, it won't turn back on again, at least not immediately. In fact, it might take more than an hour before it turns on again. I considered the possibility of overheating. I found posts with other users describing the same, but the advice was to clean the contacts. My contacts are not the issue. Because of the small mass of the whole unit, it seemed unlikely that it would take hours for it to cool sufficiently. I also found that if I swapped the battery, it would turn on immediately, and so ruled out overheating or any kind of protection circuit.

Instead, I found that after just a few minutes of use, the I92 battery's voltage drops to .8V. It slowly creeps back up about 0.001 of a volt every ten to twenty seconds. After many hours or perhaps even the next day, it will rise back to 1.4V or more. The battery would almost certainly continue to provide sufficient voltage as long as I kept the light on, but as soon as I turn it off, the output voltage drops.

I suspect something is going on with the battery's internal resistance, but I don't pretend to understand it fully. If I put a new I92 in there, it will possibly last for up to an hour at 80 lumens (Fenix's claim), but if I turn it off after only a few minutes use, the output voltage will be too low until it apparently recovers. This isn't just one I92, or a batch of them. This has been going on for three years with many batteries over the years.

What is it that I don't understand about the I92? At this point, it seems greatly advantageous to switch to regular alkalines or possibly even NiMh for cold weather.

The damn thing failed me most recently caving. Obviously I wasn't depending on it for anything extreme, but after turning on my LD01 I had to exit the cave early, and when I wanted to re-enter, it wouldn't turn on. I had to explore the cave with the light of a phone screen. About a year ago it also failed me on a bike ride at night in a dark forest. I only needed enough light to keep me on the paved path, but made the mistake of turning it off for a moment and ended up getting along by will alone.

Now I know that both times it was not the Fenix, but the I92 that failed me, and a regular alkaline would not have.
 

hiuintahs

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I've found an Energizer Ultimate Lithium AAA cell's output voltage drops to an unusable state after a few minutes use and takes many hours to recover, whereas a regular alkaline battery seems to work fine in my single AAA cell LED flashlight.

.........I found that after just a few minutes of use, the I92 battery's voltage drops to .8V. It slowly creeps back up about 0.001 of a volt every ten to twenty seconds. After many hours or perhaps even the next day, it will rise back to 1.4V or more. The battery would almost certainly continue to provide sufficient voltage as long as I kept the light on, but as soon as I turn it off, the output voltage drops.

I suspect something is going on with the battery's internal resistance, but I don't pretend to understand it fully. If I put a new I92 in there, it will possibly last for up to an hour at 80 lumens (Fenix's claim), but if I turn it off after only a few minutes use, the output voltage will be too low until it apparently recovers. This isn't just one I92, or a batch of them. This has been going on for three years with many batteries over the years.

What is it that I don't understand about the I92? At this point, it seems greatly advantageous to switch to regular alkalines or possibly even NiMh for cold weather.....
That is all interesting and I'm at a loss to say what is going on without doing a test myself. Since I have a bunch of the L91's and L92's, you're making me want to do my own test. I can only do data logging run time tests with a light meter but what needs to be done is a load test showing voltage vs time for the 3 different batteries (L92, alkaline and Eneloop) to get a comparison. If anyone knows of an inexpensive data logging piece of equipment, that is something that I might be interested in getting.
 

Crazyeddiethefirst

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I too use a lot of Energizer Lithiums, and have never experienced anything like it. I will now see if I can purposely cause a similar behavior. It may be a week or two until I can follow up....
 

archimedes

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Re: "Ultimate Lithium" vs Alkaline AAA in single cell LED flashlight

Yes, looking forward to more info ... very odd

OP ... what is "a few minutes" ? 3 ? 5 ? 10 ?
 
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Ladd

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Re: "Ultimate Lithium" vs Alkaline AAA in single cell LED flashlight

Hard to imagine what is going on here. Lithium batteries have been very reliable for me.
 

fresh eddie fresh

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Re: "Ultimate Lithium" vs Alkaline AAA in single cell LED flashlight

I use Energizer lithium AAs in quite a few lights and have never had any trouble, I haven't tried any AAAs, though.
 

jon_slider

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if I use the light for several minutes and turn it off, it won't turn back on again,
...
I found posts with other users describing the same
...
This has been going on for three years with many batteries over the years.
...
The damn thing failed me most recently caving.
...
About a year ago it also failed me on a bike ride at night in a dark forest.
...
I know that both times it was not the Fenix, but the I92 that failed me

sounds like you dont change batteries soon enough, and you dont carry a spare

suggestions
1. Carry a spare battery (or even a spare flashlight)

The first time your light fails to turn on, insert a fresh battery.
If the light does not turn on with a fresh battery, change flashlights.

Do not keep reusing a battery whose voltage drops to a level that will not turn on the light.
It does not matter that a spent battery rebounds after a few hours. It will fail again and again.

2. Get eneloop batteries. Do not wait until an Eneloop fails to turn your light on.
Change eneloop batteries when they fall below 1.2 volts, or once a week.
They are easy to recharge, and a fresh battery is brighter than a depleted one.

speculation
the first time your light fails to turn back on, it is because the battery voltage has fallen below the minimum required to turn the light on. this is the sign you need a new battery.

for some reason instead of replacing the battery, you let it rest, and then keep having the same problem..

my guess is you think the battery should last longer than it actually does, so instead of replacing it, you keep using it.. clearly that strategy is not working :)
 

archimedes

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Re: "Ultimate Lithium" vs Alkaline AAA in single cell LED flashlight

Maybe I misunderstand the OP, but my impression was he was experiencing this with new / fresh / full batteries, and every time.

He discusses changing out partly used batteries for fresh batteries "proactively"
 
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mdorian

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Re: "Ultimate Lithium" vs Alkaline AAA in single cell LED flashlight

I "discovered" the Energizer Ultimate Lithium AA's after my first year of backpacking. Obviously the weight difference isn't HUGE, but it is definitely noticeable when every ounce counts. The cold-weather performance -vs- alkaline is pronounced. We use them in Garmin Rino 120 GPS/walkie and side-by-side the one with lithium batteries transmit further and last much longer (leads to additional weight savings).
 

jon_slider

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Re: "Ultimate Lithium" vs Alkaline AAA in single cell LED flashlight

He discusses changing out partly used batteries for fresh batteries "proactively"

the way I read it, he changes batteries ("proactively"?) after "several months"

Although I use my light perhaps a half-dozen to a dozen times a week, I usually only need a for a few seconds at a time. A single AAA lasts several months or more before I change it, often proactively to ensure it doesn't die at the wrong time.

However, I've found that if I use the light for several minutes and turn it off, it won't turn back on again, at least not immediately. In fact, it might take more than an hour before it turns on again.

imho, the first time a battery fails to turn on, it should be replaced immediately, instead of letting it rest and then continuing to use it.
 
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jon_slider

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I remember another newbie poster that decided the problem with failure to turn on, or suddenly turning off, after repeated "resting" of the battery, was caused by their Lumintop Tool, (instead of blaming the batteries like this OP does).

imo both posters are simply waiting too long to replace their batteries. They run them down, and when they fail, instead of putting in a fresh battery, they let the battery "rest", and then it works again. But not for long, so they think there is something wrong with the hardware (battery or flashlight)..

imo the problem is "software" related.. operator misunderstanding and mistaken expectations, about battery life.

none of the other posters in this thread use a "rest" cycle, and none of them have experienced what the OP describes: being unable to turn a light on until it rests for an hour

any flashlight strategy that includes, "resting" the battery, to get the light to work again, is best abandoned, in favor of a fresh battery. :)

==
A story to illustrate

Dont Flog your Squirrels without Feeding them between Races

Pretend a battery has 100 squirrels inside, running inside little squirrel cage wheels.

And pretend the battery is in a light that can produce 100 lumens, when all the squirrels are running at full speed.

Now turn the light on until it stops working. Squirrels are exhausted. They collapse, and slowly start to catch their breath. Then the boss switches the light back on.. poor squirrels, they give it their best but after a very brief moment of glory, again collapse, now not only exhausted, but also undernourished and dehydrated.

They gasp for breath as they lie panting desperately to regain their energy.. but lacking any nourishment appearing, their breathing slows, and just as they are about to go into hibernation until the next feeding and recharge..

The boss switches the wheels on again! Poor Squirrels!
 
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LedTed

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Marshal from Going Gear has assured us that bad batteries (even fresh out of their package) are the first culprit and main suspect of erratically acting flashlights.

I had a fresh four pack or Enigizer alkaline AAs all fail (with 0 unloaded volts) directly from their package.

Something to check anyway.
 

eekazum

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I remember another newbie poster that decided the problem with failure to turn on, or suddenly turning off, after repeated "resting" of the battery, was caused by their Lumintop Tool, (instead of blaming the batteries like this OP does).

imo both posters are simply waiting too long to replace their batteries. They run them down, and when they fail, instead of putting in a fresh battery, they let the battery "rest", and then it works again. But not for long, so they think there is something wrong with the hardware (battery or flashlight)..

imo the problem is "software" related.. operator misunderstanding and mistaken expectations, about battery life.

none of the other posters in this thread use a "rest" cycle, and none of them have experienced what the OP describes: being unable to turn a light on until it rests for an hour

any flashlight strategy that includes, "resting" the battery, to get the light to work again, is best abandoned, in favor of a fresh battery. :)

==
A story to illustrate

Dont Flog your Squirrels without Feeding them between Races

Pretend a battery has 100 squirrels inside, running inside little squirrel cage wheels.

And pretend the battery is in a light that can produce 100 lumens, when all the squirrels are running at full speed.

Now turn the light on until it stops working. Squirrels are exhausted. They collapse, and slowly start to catch their breath. Then the boss switches the light back on.. poor squirrels, they give it their best but after a very brief moment of glory, again collapse, now not only exhausted, but also undernourished and dehydrated.

They gasp for breath as they lie panting desperately to regain their energy.. but lacking any nourishment appearing, their breathing slows, and just as they are about to go into hibernation until the next feeding and recharge..

The boss switches the wheels on again! Poor Squirrels!

Dang man, either you copied/pasted that from somewhere or you have some talent with storytelling! Ima tell that one to my kids if they try to mess with my lights!
 

Lynx_Arc

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It sounds like to me your battery is dead, perhaps you left the light on and didn't notice it as LED lights with boost circuits can shut off when they drain the battery too low and turning them off allows the battery voltage to rise above minimum levels then the current draw from the battery drops it back down again below minimum.
 
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parnass

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... Energizer Ultimate Lithium AAA cell ....

Instead, I found that after just a few minutes of use, the I92 battery's voltage drops to .8V. It slowly creeps back up about 0.001 of a volt every ten to twenty seconds. After many hours or perhaps even the next day, it will rise back to 1.4V or more. The battery would almost certainly continue to provide sufficient voltage as long as I kept the light on, but as soon as I turn it off, the output voltage drops.
...

Did you measure the battery voltage while the battery is under load? Unlike alkaline batteries, open circuit voltage measurement is not a reliable way to judge a lithium battery's condition.
 

RobertMM

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That cell is obviously dead. I've had experience only with AA/L91, but observed nothing less than great performance.

I believe at 1.5V no load, they are almost dead. Fresh from the pack I've measured some to be 1.75Volts.
 

jon_slider

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you have some talent with storytelling! Ima tell that one to my kids if they try to mess with my lights!

LOL! Thank You. Ive been making up stories for my kids on the fly at bedtime for many years. I usually have no idea how they are going to turn out, until I hear them myself :)

open circuit voltage measurement is not a reliable way to judge a lithium battery's condition.
I learned something new, thanks!

That cell is obviously dead.

agreed..

joking: Magical thinking says it should last an hour on high, every time I turn it on.. isnt that right?.. and then its supposed to drop to 50% half way through, right? If it does not turn on after a few minutes on high, then the problem is that Lithium batteries dont last very long… ROTFL

respect to the OP, just funning at your expense, dont take it personal.. I resemble your learning curve..

Elvis has Left the Building :)
 

Woods Walker

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I am not putting spill their toxic guts alkaline batteries in my gear unless lost in the woods being chased by a herd of walkers and desperately need the light. Even then maybe not.
 

eekazum

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I am not putting spill their toxic guts alkaline batteries in my gear unless lost in the woods being chased by a herd of walkers and desperately need the light. Even then maybe not.

Lol reminds me if that movie It where the kid screams "this is battery acid!" at pennywise the clown.
 
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