Compare and Contrast two versions of XTAR 1.5V AA LiIon with USB-C

I received some XTAR LR 3000mAh 1.5V LiIon as a gift from XTAR, after doing a review of some of their other batteries and chargers. This 3000mAh version, is the type whose voltage declines at a tapered rate.

I previously have been using the CLR 2450mAh version, whose voltage stays at 1.5V for the first 75% of the runtime, and then at 1.20V switches to that Voltage, to help give advance Low Voltage Warning, before the battery shuts off completely. I posted a review here.

These are the discharge curve types for the two battery designs:




I used an Emisar KR1AA w NTG 4200K, with ceiling set to 90/150 = 340 lumens

My testing goal was to determine at what Voltage the LR 3000mAh design could no longer start, when not hot, at my selected ceiling.

my results are that at 1.30V it still started at 340 lumens
(with breaks in the On time, to let the light cool down about every 10 minutes)

at 1.26V it started at 160 lumens..

The Thermal Step down in the KR1AA reduced output to between 160-180 lumens as the light heated up, this took about 5 minutes, each time I restarted the test from 340 lumens, when the light had cooled down.

What I learned is that:
Below 1.30V, the declining voltage type battery can no longer hit my chosen ceiling of 340 lm

We can infer that the constant 1.5V battery, when it switches to the 1.2V low voltage warning phase, also can not sustain 340 lm

my conclusion is that the two versions of the battery have very similar output performance..
their output is limited primarily by Thermal Step Down, Not by the Voltage

imo these 1.5V LiIon batteries are most useful for low and medium outputs, with the ability to produce a higher output briefly. They seem to work similarly well as Eneloop, with the added convenience of USB-C charging and longer runtime.

Compared to the sustained 1.5V design, rated 2450mAh, I see a couple of Advantages to the declining Voltage version rated 3000mAh:

1. Voltage check gives me more advance notice, to help me anticipate when it will need to be recharged...
2. More capacity, so it has a runtime advantage.

jon_slider said:

I received some XTAR LR 3000mAh 1.5V LiIon as a gift from XTAR, after doing a review of some of their other batteries and chargers. This 3000mAh version, is the type whose voltage declines at a tapered rate.

I previously have been using the CLR 2450mAh version, whose voltage stays at 1.5V for the first 75% of the runtime, and then at 1.20V switches to that Voltage, to help give advance Low Voltage Warning, before the battery shuts off completely. I posted a review here.

These are the discharge curve types for the two battery designs:

View attachment 96516


I used an Emisar KR1AA w NTG 4200K, with ceiling set to 90/150 = 340 lumens

My testing goal was to determine at what Voltage the LR 3000mAh design could no longer start, when not hot, at my selected ceiling.

my results are that at 1.30V it still started at 340 lumens
(with breaks in the On time, to let the light cool down about every 10 minutes)

at 1.26V it started at 160 lumens..

The Thermal Step down in the KR1AA reduced output to between 160-180 lumens as the light heated up, this took about 5 minutes, each time I restarted the test from 340 lumens, when the light had cooled down.

What I learned is that:
Below 1.30V, the declining voltage type battery can no longer hit my chosen ceiling of 340 lm

We can infer that the constant 1.5V battery, when it switches to the 1.2V low voltage warning phase, also can not sustain 340 lm

my conclusion is that the two versions of the battery have very similar output performance..
their output is limited primarily by Thermal Step Down, Not by the Voltage

imo these 1.5V LiIon batteries are most useful for low and medium outputs, with the ability to produce a higher output briefly. They seem to work similarly well as Eneloop, with the added convenience of USB-C charging and longer runtime.

Compared to the sustained 1.5V design, rated 2450mAh, I see a couple of Advantages to the declining Voltage version rated 3000mAh:

1. Voltage check gives me more advance notice, to help me anticipate when it will need to be recharged...
2. More capacity, so it has a runtime advantage.

Click to expand...

Woah! those have a higher mAh rating than the CLR4300? I find myself appreciating the 4300 because they maintain 1.5V until somewhere around 35%, at which point they do the taper. The 3000mAh seem to exhibit alkaline behavior?

dc38 said:

those have a higher mAh rating than the CLR4300?

Click to expand...

correct ;-)
the LR are 3000mAh
the CLR are 2450mAh

dc38 said:

The 3000mAh seem to exhibit alkaline behavior?

Click to expand...

true
similar declining curve, but at an overall higher Voltage, so, longer runtime and higher output:

jon_slider said:

correct ;-)
the LR are 3000mAh
the CLR are 2450mAh


true
similar declining curve, but at an overall higher Voltage, so, longer runtime and higher output:

View attachment 96524

Click to expand...

i have the 2700mAh ones with 4300mWh, they sustain 1.5V for about 65% of the capacity, then do a taper to enter low voltage mode. I have to do another runtime test at the levels you tried, 90/150, but I believe I tested at 100/150 a little while back and got around 75 minutes

dc38 said:

runtime test at the levels you tried, 90/150

Click to expand...

fwiw, that 90/150 = 340 lm output ceiling is not sustainable with 1.5V LiIon.

The heat from the Voltage converting chip, builds up rather quickly and causes Thermal StepDown to drop output to about half of that starting level.

I think a ceiling of 70/150 = about 140 lm, is closer to the Sustainable Output for 1.5V LiIon, in a KR1AA.

I think normal 14500 LiIon is going to come closer to sustaining 90/150 ceiling, because the 14500 does not add as much heat as a 1.5V chip

jon_slider said:

fwiw, that 90/150 = 340 lm output ceiling is not sustainable with 1.5V LiIon.

The heat from the Voltage converting chip, builds up rather quickly and causes Thermal StepDown to drop output to about half of that starting level.

I think a ceiling of 70/150 = about 140 lm, is closer to the Sustainable Output for 1.5V LiIon, in a KR1AA.

I think normal 14500 LiIon is going to come closer to sustaining 90/150 ceiling, because the 14500 does not add as much heat as a 1.5V chip

Click to expand...

I got something like that, the throttling dropped the brightness and skewed the results the first time, like...90 minutes or something, I can't remember. With cooler ambient temps I got the 70 minute times

Imo 1.5V LiIon are best suited for outputs below about 200 Lumens (step 5 of 7 or less, on a D3AA with default ceilings, equivalent to ceiling 80/150 on a KR1AA)..

Runtime tests are most useful when they show a chart of the output change over time, such as this D3AA test on Eneloop by Zeroair:

R

One of the more esoteric reasons I like to use 1.5V LiIon is because they produce less Riple in my AA Zebra than Eneloop or LiIon:



these images come from the Opple 3 Flicker Index tests. (this is not about Visible flicker)

For illustration purposes I call your attention to the Level 9 charts: which show 2% Riple for 1.5V LiIon with fixed 1.5V output, 40% Riple for Eneloop, and 62% Riple for 14500:



I have not (yet) checked whether the 3000mAh 1.5V LiIon with Declining Voltage has similar Very Low Riple as the 2450mAh version that has sustained 1.5V output.

My guess is the sustained 1.5V is responsible for the lower Riple score.

jon_slider said:

One of the more esoteric reasons I like to use 1.5V LiIon is because they produce less Riple in my AA Zebra than Eneloop or LiIon:

View attachment 96560

these images come from the Opple 3 Flicker Index tests. (this is not about Visible flicker)

For illustration purposes I call your attention to the Level 9 charts: which show 2% Riple for 1.5V LiIon with fixed 1.5V output, 40% Riple for Eneloop, and 62% Riple for 14500:

View attachment 96564

I have not (yet) checked whether the 3000mAh 1.5V LiIon with Declining Voltage has similar Very Low Riple as the 2450mAh version that has sustained 1.5V output.

My guess is the sustained 1.5V is responsible for the lower Riple score.

Click to expand...

most likely the boost-buck nature of the driver...sub 3V probably boosts then bucks the boost down to the required voltage, over 3.7V might do the same, or just buck, and 1.5V is probably right in the range to boost to 3V and sustain...maybe

dc38 said:

1.5V is probably right in the range to boost to 3V and sustain

Click to expand...

agree
@sbslider has also pointed out that he believes that increases runtime:

sbslider said:

The big advantage of a rechargeable 1.5V Li cell is that it holds the voltage to the light at 1.5V. So the light will demand less current, and the runtime of the cell will increase, pretty significantly.

Click to expand...

now an observation about the 3000mAh 1.5V LiIon, which does not sustain a constant 1.5V, and instead has a constantly declining Voltage, that can be read in an Anduril light using the Battery Check function, or with a DMM..

Im tempted to put one of the 3000mAh 1.5V LiIon that have the measurable Voltage change, in my car for the rest of the summer, so I can check how well is maintains its Voltage through the remaining summer heat. Along with a freshly charged new 1900mAh Eneloop. So I can compare the Voltages when I change out my car flashlight batteries on Nov 1st, (when Daylight Savings time ends).

I live in an area where the high temps are generally below 95F and the inside of my car usually does not go above 115F in the cargo area (parked in the sun with tinted windows and a sunscreen inside the windshield).

I usually reserve my car light use to Eneloop.. but Im wondering whether 1.5V LiIon might work just as well in my climate.

Here is a very interesting observation regarding the difference in Riple from two different Voltage Levels of a pair of Eneloops:



Lower Voltage produces Higher Riple Depth, and Higher Flicker Index. Higher Voltage produces much less Riple, and Much Lower Flicker Index.

This suggests to me that a 1.5V LiIon 2450mAh version which has Sustained 1.5V output is going to offer lower Riple and lower Flicker Index, than a 1.5V LiIon 3000mAh version which has Declining Voltage.

Just to clarify, a cell that holds a constant voltage will improve run time in a regulated light, like my zl hc53c. But in an unregulated light, it will have a shorter run time.
Regulated light = constant output level for varying cell voltage. Higher voltage means lower current for a given light power.

sbslider said:

Higher voltage means lower current

Click to expand...

thank you for sharing that insight..
it has helped me appreciate the value of 1.5V LiIon with constant 1.5V output even more

I also like that 1.5V LiIon weigh less than Eneloop
Plus I appreciate the convenience of the 1.5V LiIon that offer built in USB charging..
My Zebras run particularly well on them:

The 3000mAh one on the right is the measurably declining Voltage type, I put one in the car, along with an Eneloop, so I will be able to check their Voltage at the end of Daylight Savings time..

jon_slider said:

thank you for sharing that insight..
it has helped me appreciate the value of 1.5V LiIon with constant 1.5V output even more

I also like that 1.5V LiIon weigh less than Eneloop
Plus I appreciate the convenience of the 1.5V LiIon that offer built in USB charging..
My Zebras run particularly well on them:

View attachment 96648

The 3000mAh one on the right is the measurably declining Voltage type, I put one in the car, along with an Eneloop, so I will be able to check their Voltage at the end of Daylight Savings time..

Click to expand...

I believe these 1.5's self discharge are relatively high when left alone, and are intended to be regularly used

dc38 said:

I believe these 1.5's self discharge are relatively high when left alone, and are intended to be regularly used

Click to expand...

thank you for the warning,

I have heard that claim too,
but without any specific details about timeframe,
nor any evidence referenced

That is why I am doing my own long term storage test for the next few months
using the version that has measurable Voltage change
alongside Eneloop for comparison

The test is during summer, in a car,
which should be especially challenging for LiIon

so if they are going to have a high discharge rate,
I expect it will show up easily, as a loss of Voltage during storage

Did you see this reference of use in trail cameras in Winter?:

XTAR Light said:

After several months outdoors and hundreds of captures, the batteries were still powerful.

Click to expand...

Cold weather is also known to reduce Voltage and runtime capacity.. so I found that report encouraging...

If you find any test results that would add useful evidence, please share.

jon_slider said:

thank you for the warning,

I have heard that claim too,
but without any specific details about timeframe,
nor any evidence referenced

That is why I am doing my own long term storage test for the next few months
using the version that has measurable Voltage change
alongside Eneloop for comparison

The test is during summer, in a car,
which should be especially challenging for LiIon

so if they are going to have a high discharge rate,
I expect it will show up easily, as a loss of Voltage during storage

Did you see this reference of use in trail cameras in Winter?:


Cold weather is also known to reduce Voltage and runtime capacity.. so I found that report encouraging...

If you find any test results that would add useful evidence, please share.

Click to expand...

I primarily got mine for cam usage, they do quite well in the winter. With constant triggering (about an hour to 2 hours cumulative a day) I think I get about 1.5 months per set. If there's basically very little triggers, it'll last anywhere between 3-6 months. Not bad in my book. I also have a few sets dedicated for 2series lights which don't have regulation, cumulatively, I believe I get over 12 hours at ~30ish lumens, maybe closer to 16 hours. One of these days I'll do a proper run test.

I really think that the kr1AA at whatever specific level is probably one of the better indicators, as the brightness seems pretty consistent across the board.