LiteFlux LF5XT Review: RUNTIMES, BEAMSHOTS, COMPARISONS, and more!

gadgetnerd

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A theory about this: the light uses a microprocessor, and the minimum voltage for it to run is 1V. I think that when the voltage drops below that, the designers at LiteFlux thought that although it would still work, it would become unpredictable and might even randomly rewrite the EEPROM etc. So they made the light turn off at 1V, and allowed the user as a compromise to use the light again by doing the "rest the cell for a while" trick.

It's not really battery protection, but microprocessor protection with a nice side benefit.

One way to confirm this is to pull the light apart and see what processor it uses. Anybody up for it?

Also, I've heard reports that the "battery" protection doesn't work for 14500s, as in it only cuts off at 1V, which by then the cell is damaged. Can you confirm this?


Very interesting theory rotototo. I'd love to hear from Khoo or LiteFlux to confirm/deny. Recalling earlier threads in which the challenge of reliably running a MCU torch off 1.5V power source, I think that the microprocessor runs at much more than 1V, but below that the step up can't reliably supply the voltage it needs. But then again, I'm not a torch engineer!
 

jackcselab

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Mar 3, 2006
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A theory about this: the light uses a microprocessor, and the minimum voltage for it to run is 1V. I think that when the voltage drops below that, the designers at LiteFlux thought that although it would still work, it would become unpredictable and might even randomly rewrite the EEPROM etc. So they made the light turn off at 1V, and allowed the user as a compromise to use the light again by doing the "rest the cell for a while" trick.

It's not really battery protection, but microprocessor protection with a nice side benefit.

One way to confirm this is to pull the light apart and see what processor it uses. Anybody up for it?
Liteflux's designer answered this question at my3c forum in Taiwan.
LF5XT's boost circuit design has something different from traditional design. It will shutdown at about 0.7V~0.8V.

PS:My english is very poor and I am not a engineer. So I can't explain here.

Also, I've heard reports that the "battery" protection doesn't work for 14500s, as in it only cuts off at 1V, which by then the cell is damaged. Can you confirm this?

I have heard two cases including mine. It is happened only at 14500 100% setting. At other brightness setting, the battery protection work correctly.

I don't know it is special cases or general cases. I need more report to confirm it or not.
 

jackcselab

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Mar 3, 2006
Messages
31
A theory about this: the light uses a microprocessor, and the minimum voltage for it to run is 1V. I think that when the voltage drops below that, the designers at LiteFlux thought that although it would still work, it would become unpredictable and might even randomly rewrite the EEPROM etc. So they made the light turn off at 1V, and allowed the user as a compromise to use the light again by doing the "rest the cell for a while" trick.

It's not really battery protection, but microprocessor protection with a nice side benefit.

One way to confirm this is to pull the light apart and see what processor it uses. Anybody up for it?
Liteflux's designer answered this question at my3c forum in Taiwan.
LF5XT's boost circuit design has something different from traditional design. It will shutdown at about 0.7V~0.8V.

PS:My english is very poor and I am not a engineer. So I can't explain here.

Also, I've heard reports that the "battery" protection doesn't work for 14500s, as in it only cuts off at 1V, which by then the cell is damaged. Can you confirm this?

I have heard two cases including mine. It is happened only at 14500 100% setting. At other brightness setting, the battery protection work correctly.

I don't know it is special cases or general cases. I need more report to confirm it or not.
 

gadgetnerd

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Messages
786
Location
Brisbane, Australia
Liteflux's designer answered this question at my3c forum in Taiwan.
LF5XT's boost circuit design has something different from traditional design. It will shutdown at about 0.7V~0.8V.

PS:My english is very poor and I am not a engineer. So I can't explain here.



I have heard two cases including mine. It is happened only at 14500 100% setting. At other brightness setting, the battery protection work correctly.

I don't know it is special cases or general cases. I need more report to confirm it or not.

Thanks very much for that information. It's great having chinese speakers able to provide technical data from some of the other forums.
 

rotototo

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Mar 26, 2008
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Liteflux's designer answered this question at my3c forum in Taiwan.
LF5XT's boost circuit design has something different from traditional design. It will shutdown at about 0.7V~0.8V.

PS:My english is very poor and I am not a engineer. So I can't explain here.



I have heard two cases including mine. It is happened only at 14500 100% setting. At other brightness setting, the battery protection work correctly.

I don't know it is special cases or general cases. I need more report to confirm it or not.

Could you provide a link to his post? I could translate.
 

selfbuilt

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I'm anxious to hear your thoughts on that aspect of the light. I like the idea of a much brighter spill, even at the expense of spill width. In actual usage though, I'm not so sure. I'll be waiting for your report :thumbsup:
Just added some EDC comments to the very end of the first post. I'm actually rather surprised that I hadn't found the narrower beam to be an issue in practice - until I realized the involuntary adaptation that I've been doing (i.e. holding the light higher up than I normally do, casting a wider spill).

It's funny how your unconscious plays tricks on you - despite my conscious attempt to gauge differences in the beams, I had quickly adapted to normalize out the differences! Goes to show you the hazards in trying to over-analyze some these subjective impressions ... :whistle:
 

selfbuilt

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selfbuilt great review,can you "roughly" tell me where the low comes on the Novatac scale in lumens,thanks
Actually, I can tell you pretty exactly. According to my lightbox, my LF5XT min has almost identical output to my Novatac level #10, which is rated at 1.9 lumens.

My original NDI min was a good match to level #9, 1.3 lumens.

And my D10 min is a good match to level #5, 0.33 lumens.

seriously - you're reviews are stinking awesome
:)
 

selfbuilt

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Just an update, but Khoo has presented some possible solutions from Liteflux for dealing with the issue of the light turning itself off when placing down in candle mode.

Personally, I can live with the issue in mine, but the options are there if you want them.

:wave:
 

Rob187

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Feb 26, 2006
Messages
400
Location
Sydney, Australia
What settings did everyone go with on the LF5XT?

Importantly for my settings, I figured out that the percentage 'brightness' report the LF5XT gives you is a power figure not an output figure. Like all LEDS and as shown by selfbuilts graphs, the LED efficiency decreases as power is increased. After much experimentation with different settings and reviewing I have settled on the following:

Momentary: off
Memory on:
No. of Modes: 5
Mode 1: 42% (~50% brightness)
Mode 2: 18% (~25% brightness)
Mode 3: 6% (~11% brightness)
Mode 4: 1% (~ 3% brightness)
Mode 5: Single beacon flash/4s at 1% power
Overdischarge warning: off

Don't hold me too closely to my brightness estimated outputs - they are just my best estimates and are not scientifically measured...

The only drawback with these settings is that 100% power cannot be latched on - it can only be accessed with PH from on or off.

How is your LF5XT set up?
 

selfbuilt

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gMomentary off
Memory off
Overdischarge protection on
Mode 1: 1%
Mode 2: 8%
Mode 3: 30%
Mode 4: 100%
Mode 5: locator beacon at 1%

So mine always comes on at lowest mode, which makes it useful around the house at night.
That's pretty much exactly how I run mine as well. I also like having it always come on at the lowest mode, then step up in brightness.
 
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Rob187

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It's interesting that we have each set our lights up in a quite similar way.

I know there are a few of these lights out there with other CPFers so let's hear what your setups are please.
 

BabyDoc

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Jan 29, 2008
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Beachwood, Ohio
This is how I run mine:

Mode 1: 1 percent
Mode 2: 15 percent
Mode 3: 33 percent
Mode 4: 50 percent
Mode 5: 75 percent
Memory: On
Momentary: On
Battery Protection:OFF

The reason I left momentary on is it gives me instant momentary on in any mode with a PH (there isn't a 0.4 sec delay). In addition, with momentary on, the brief flash before going constant with Cx1 is a visual guide to pressing the switch just long enough before release to get consistent constant turn on. ( As many have reported, on cold starup, if Cx1 is too brief, the light fails to go constant.) I leave memory on in order to preset light for any mode. In that way, when with PH, I can get an instant momentary on, in any mode, not just mode 1.

I set my highest mode setting at 75% , which is close to Max instead of Max, because I don't want to accidentally leave it constantly on Max and eat up my runtime. Yet if I really want max, I can do a PH and get Max on momentary.


Incidentally, I discovered that it is easier to program the light with memory off. In that way you are always starting with mode 1. Count modes from there, and you can easily tell which mode you are in that you may want to change. Once all 5 modes were programmed, I then turned memory back on.

This may be obvious to everyone who has the LF5XT, but when doing a mode adjustment, Cx1, and Cx2, lets you change up and down in larger brightness increments than doing Cx1+PH or Cx2+PH which ramp the light up and down quite slowly. Once I set the level to my approximate desired level with Cx1 or Cx2, I then ramped up and down to fine tune it to exact desired settings. Using Cx5, repeatedly, lets you see exactly what your last adjustment did. Get it exactly where you want it, then 3xC+PH to save it.
 
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baterija

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Feb 7, 2008
Messages
1,053
It's interesting that we have each set our lights up in a quite similar way.

A slightly less similar way. :D

Mode 1: 85 percent
Mode 2: 1 percent
Mode 3: 8 percent
Mode 4: 33 percent
Mode 5: default SOS
Memory: Off
Momentary: On
Battery Protection:OFF
 
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