New K2 2-stage flashlight from FifthUnit.com: $27 shipped

Usually, I don't spring for a new flashlight until I've read the reviews and impressions of the knowledgeable "early adopters" here on CPF, but I just made an exception. I had an initial good experience with a small purchase from FifthUnit.com, and was impressed with their after-the-sale follow-up and e-mail responsiveness. I mentioned to Bonnie in Customer Service that I recently had seen a 2-stage K2 light on ebay, and hoped that they might consider adding one to their line-up. Sure enough, she let me know that that would happen within a few days, and today I saw it on their website: www.FifthUnit.com.

As I say, I normally wouldn't jump in blindly, but at ~$27 shipped for a 2-stage K2, what the heck. I'll post my impressions when it arrives.

doesnt seem regulated

-david

cheapo said:

doesnt seem regulated

-david

Click to expand...

You may be right, but I figure with RCR123As, there may be a decent discharge curve anyway. If not, it's easy enough to pop the cells back in the charger and top 'em off.

For the price, I'm not expecting all the bells and whistles, I'm just interested in trying out a K2. The 2-stage feature and being 3.6v li-ion capable are more important to me.

ships in 4 days and delivery in 16 days with airmail? It's more like snail mail to me (more like row-boat mail)... Depending on when it gets shipped it could be 3+ to 4 weeks for something that is supposebly in-stock... That's just too long a wait to hold up my greens, albeit lowly $23... Wake me up when you guys get one in hand and put it through its paces...

Usually resistor regulated.

I tried a K2 U-bin in my golston. No noticable difference from a LUX III U-bin. K2 has less runing time. The K2 Vf was 4.02 @ 1050mAh. The LUX III Vf was 3.37 @ 1050mAh.

this is one thats got me :thinking: :shrug:

K2 LED
Power: 3 x AAA Batteries

:hahaha:"True 7 Watts"

http://contents.fifthunit.com/html/products.5th/sku.851.html

where are they getting 1500 mAh AAA's ?

..
... Hi AFAustin ,

I am beginning to see a trend in these lights - especially the ones from 5th-unit.

They seem to be making them more cheaply now . More intended as *throw-away lights* if they quit . Not good *hosts* for mod projects or improvements .

Thinner aluminum tubes & heads - causing less heat absorption material - so they get hotter , quick.

Press-fitted construction / thin pressed- in aluminum heat sink for star mounting / no threads on heat-sink so it's non-removeable for easy modding / battery tube not thick enough for bore-out modding....... OH YEAH , and lastly , tubes not big enough for PRO-tected RE- chargeables !

Thats what I'm seeing , coming from 5th-unit - for 22 to $28 .

When you get this one - please let us know if it's constructed as I described , and let us know your feelings about this .

Do you think these lights are starting to get less desireable due to cheaper build quality - as I do ?

( I got the Kenbar/True 8 Watt ...... and those were my feelings about it )

Thanks ...... TooManyGizmos .
.

Randy Shackleford said:

this is one thats got me :thinking: :shrug:
K2 LED
Power: 3 x AAA Batteries
:hahaha:"True 7 Watts"
http://contents.fifthunit.com/html/products.5th/sku.851.html
where are they getting 1500 mAh AAA's ?

Click to expand...

It's do-able.
Electrolumens My Little Friend is 3*3 wats = 9 watts.
Power 4 AAA
Runtime 30 mins on 1000 mAH; 24 min on 800 mAH
Electrolumens sells 1000 mAH AAAs on his website; I got Duracell 1000 mAH Duracells at Walmart Canada.

VF1Jskull1 said:

ships in 4 days and delivery in 16 days with airmail? It's more like snail mail to me (more like row-boat mail)... Depending on when it gets shipped it could be 3+ to 4 weeks for something that is supposebly in-stock... That's just too long a wait to hold up my greens, albeit lowly $23... Wake me up when you guys get one in hand and put it through its paces...

Click to expand...

Patience! 16 days. Wow that's quick.
Paid for My Little Friend in Feburary. Got it June 26. About another 100 CPFers are still waiting for theirs.
Peak Pacific takes just as long between annoucement and shipping.
LRI proton took 1-1.2 years.
MagLED took 2-1.2 years. The AA versions will be closer to 3.

TooManyGizmos said:

I am beginning to see a trend in these lights
They seem to be making them more cheaply now .
Thinner aluminum tubes & heads
Press-fitted construction / thin pressed- in aluminum heat sink for star mounting
Do you think these lights are starting to get less desireable due to cheaper build quality - as I do ?

Click to expand...

Found a holster for My Little Friend - a neoprene cellphone holder. The weight of My Little Friend stretched the neoprene so it doesn't fit. Now I'm looking for a more rugged holster. Wish My Little Friend has thinner lighter walls.
Both my Solitaires and Dorcy AAA held up well despite the thin walls.

Originally Posted by LEDninja:
"Patience! 16 days. Wow that's quick.
Paid for My Little Friend in Feburary. Got it June 26. About another 100 CPFers are still waiting for theirs.
Peak Pacific takes just as long between annoucement and shipping.
LRI proton took 1-1.2 years.
MagLED took 2-1.2 years. The AA versions will be closer to 3."

But these non-branded chinese lights aren't custom like the MyLittleFriend. Peak and LRI are sorta custom or limited anyways.... I didn't know you can order MagLED until recently where you can get them at most walmarts or targets...

LEDninja said:

It's do-able.
Electrolumens My Little Friend is 3*3 wats = 9 watts.
Power 4 AAA
Runtime 30 mins on 1000 mAH; 24 min on 800 mAH
Electrolumens sells 1000 mAH AAAs on his website; I got Duracell 1000 mAH Duracells at Walmart Canada.

Click to expand...

so, in your example is... Duracell AAA batteries= 1000 mAh @ ~1.5V

How do you arrive at 7 watts using 3 batteries or 9 watts using 4 batterries.? :thinking:

eh. Ordered one anyways... For $27, no big deal...

Has anyone here received one yet?

TooManyGizmos said:

..
... Hi AFAustin ,

I am beginning to see a trend in these lights - especially the ones from 5th-unit.

They seem to be making them more cheaply now . More intended as *throw-away lights* if they quit . Not good *hosts* for mod projects or improvements .

Thinner aluminum tubes & heads - causing less heat absorption material - so they get hotter , quick.

Press-fitted construction / thin pressed- in aluminum heat sink for star mounting / no threads on heat-sink so it's non-removeable for easy modding / battery tube not thick enough for bore-out modding....... OH YEAH , and lastly , tubes not big enough for PRO-tected RE- chargeables !

Thats what I'm seeing , coming from 5th-unit - for 22 to $28 .

When you get this one - please let us know if it's constructed as I described , and let us know your feelings about this .

Do you think these lights are starting to get less desireable due to cheaper build quality - as I do ?

( I got the Kenbar/True 8 Watt ...... and those were my feelings about it )

Thanks ...... TooManyGizmos .

.

Click to expand...

Hi there, TMG.

Sorry to hear about the Kenbar---looks like a nice light on their webpage. After a weird "break in" experience I've posted about elsewhere, I've actually been pleased with the 1xRCR123A ""6w 2-stage" light, which I got from Dae but appears to be the same one FifthUnit sells. I'll definitely post an update on the K2 model when it gets here.

Cheers,

Andrew

Randy Shackleford said:

this is one thats got me :thinking: :shrug:

K2 LED
Power: 3 x AAA Batteries

:hahaha:"True 7 Watts"

http://contents.fifthunit.com/html/products.5th/sku.851.html

where are they getting 1500 mAh AAA's ?

Click to expand...

Randy,

That got my attention, too. They describe the light as a "Luxeon III K2"---aren't these 2 totally different emitters? I've sent FifthUnit an e-mail in hopes that they'll clarify that.

Randy Shackleford said:

so, in your example is... Duracell AAA batteries= 1000 mAh @ ~1.5V

How do you arrive at 7 watts using 3 batteries or 9 watts using 4 batterries.? :thinking:

Click to expand...

My Little Friend has 3 Lux IIIs. 3*3W=9W nominal
My Little Friend draws 3*700mA =2100mA on high.
1000mAh/2100mA=0.476h=28mins
4*1.2V=4.8V. 3.6V is dropped across the LEDs. 1.2V is used up by the dropping resistors & battery internal resistance.
Actual power used by the LEDs = 2.1A*3.6V = 7.56 watts.
Power drawn from the batteries = 2.1A*4.8V = 10 watts. (the Duracells are 1.2V NiMH)

The '7W' light is confusing. 'Luxeon III K2'. Luxeon III is a lot different than the K2.

Randy Shackleford said:

I tried a K2 U-bin in my golston. No noticable difference from a LUX III U-bin. K2 has less runing time. The K2 Vf was 4.02 @ 1050mAh. The LUX III Vf was 3.37 @ 1050mAh.

Click to expand...

For the Golston:
Actual power used by the LEDs = 1.05A*3.37V = 3.5385 watts.
Power drawn from the batteries = 1.05A*6V = 6.3 watts. If you use RCR at 7.2V you get over 7 watts.

There are 2 possibilities for 7W at 4.5V (3AAA)
1)
They are using the same LED as the 7W Golston so they also call their torch 7W.
2)
They are using a K2 driven at 1.5A.1.5A*4.5V=6.75W. AAA Alkalines won't produce 1.5A for long but they can claim it.

LEDninja said:

My Little Friend draws 3*700mA =2100mA on high.

Click to expand...

Cool. :rock: Have you tested this with a Ampmeter?

A K2 may draw ~1000mAh

Randy Shackleford said:

Cool. :rock: Have you tested this with a Ampmeter?

A K2 may draw ~1000mAh

Click to expand...

No
The calculated runtimes are very close to actuals in the review and electrolumens forums so I do not doubt the LEDs are driven at very close to the nominal 700 mA for a Lux III.
http://elektrolumens.com/LittleFriend/LittleFriend.html

ElektroLumens said:

Luxeon white K2 LED, part #: PW14-U00. Rated up to 130 lumens at 1.5 amps.

Click to expand...

http://candlepowerforums.com/vb/showthread.php?t=120640

up to 1.5A, spec is 1A.

Doubtful that the fifthunit model has a board in it.
Without a regulation board, 3AAA in series should max at ~900~1000mAh

I received an 8 watter from fifthunit on Wednesday... ordered it just to see what it was like and their shipping. I am interested in ordering a bunch of their computer items for my company. It took 11 days from placing order to ripping package open. Light arrived in a thick envelope. It was inside a plain white box just big enough for the light. No instructions.

First a couple technical measurements I quickly took at work on a lunch break:

The two stage switch measures 3.5 ohms in the high position and 11.5 in the low position.

Using two 3.6 volt 650mah unregulated lithiums: I measured the current draw from the batteries at about .7 amps on high and .3 on low. The emitter read 3.27 volts across it's leads on high. I have not tried to take it apart yet to read the current flow through the emitter. I also bypassed the switch and got .9 amps.

The beam for an 8 watt light sux! Er... I mean the beam for a Lux III is pretty nice. Good throw, nice white color, good sidespill. The reverse clickie has a good feel... flush with tail, firm but not too hard to press, two stage Hi-LOW-OFF. So far I have walked around with the light in my pocket with keys for half a day and no scratches (it's a little too big for that, but I had cargo shorts on with large pockets that day). Knurling makes grip nice but not rough feeling (which would have made it harder to pull out of a holster, something I always look at from past experience).

I tried it on two fresh Titanium primarys and laughed... they admit on the site it runs much better on RCR's and they weren't kidding. This must be from the simple resistered circuit... no regulation, no boost, no nothing. Probably the light's biggest drawback, aside from the cheap plastic lens.

As for brightness... well I would say it's a decent 3 watt beam... I have seen much dimmer 3 watters (my disappointing Gerber TX 3.0 comes to mind), somewhat dimmer, and brighter ones.

So far one quirk I had was while outside tonight it went off for a couple seconds... I reached for my EDC and it came back on.. my finger was not on the switch.

Construction? Well why rip it apart cause it's not made for modding? It's a cheap 23 dollar flashlight! I find it's construction quality fine. I have a Nuwai ALX-352L and yes it's built like a tank, but I can't remember the last time I ran over a flashlight with my car and wished it was built like a tank to survive... but I do often wish it was thinner and it's holster didn't have that plastic liner which would make the whole setup a lot easier to carry on the belt.

Anyway, for 23 bucks to my door I like it a lot as long as the runtime works out OK and it is reliable. Only time will tell.. haven't played with it enough yet to say.

I just got an e-mail about the K2... their site says they are going to post beamshots, brightness comparisons, etc on their lights.. but doesn't mention runtimes.

I agree the 7 watter on 3AAA has to be a pathetic joke. I can't imagine AAA's giving enough amperage to do much... we have seen reviews of Lux III on them before and if they really do drive the emitter bright enough the runtime is... well an Orb Raw runtime comes to mind LOL.

I'm going to order from them again and pick up a few computer items plus mor e lights.. I light the looks of the 3AA 7LED ones, for example.

This is from their recent review: http://contents.fifthunit.com/html/reviews.5th/review.001_1.html

1) 10W K2 Dual Mode flashlight


According to its manufacturer YANG, this flashlight has genuine Lumiled K2 bulb built-in. This flashlight looks like the 2) 7W flashlight. Its construction is very solid. It also features dual light output modes to save power if needed. We used the two of the recommended LIR 3.6V CR123A batteries and see how it performs:

High mode

1) Throw number (LUX): 2470 at beam center (49.70 Comparison Chart equivalent)
2) Output number (LUX): 5510 (55.10 Comparison Chat equivalent)
3) Estimated Lumens (Lumens): 76.59
4) Beam pattern:


Nikon D50, Tamron 90mm Di Marco, 1/100, F8

Low mode

1) Throw number (LUX): 1290 at beam center (35.92 Comparison Chart equivalent)
2) Output number (LUX): 2600 (26.00 Comparison Chat equivalent)
3) Estimated Lumens (Lumens): 36.14


After the test comment:
This is most powerful LED flashlight in our test. The white light produced by the LED is a high color temperature and produces good color rendition. The white light is a little toward the warm (yellow) side, which is a good thing to cut through rain and fog. The slight tint is not noticeable during normal use. The beam pattern is nice and even. It got two inner circles of central spot, while the spillbeam starts from the second circle and extend all the way to fifth circles (it keeps going but it's not showing in the picture).

Wonder how does it light performs using the 3.0V CR123A batteries? Let's give it a try too:


High mode

1) Throw number (LUX): 1970 at beam center (44.38 Comparison Chart equivalent)
2) Output number (LUX): 4070 (40.70 Comparison Chat equivalent)
3) Estimated Lumens (Lumens): 56.57

Low mode

1) Throw number (LUX): 900 at beam center (30.00 Comparison Chart equivalent)
2) Output number (LUX): 1840 (18.40 Comparison Chat equivalent)
3) Estimated Lumens (Lumens): 25.58



So, the decrease of 12% voltage (from 4.2V to 3.7V) actually hurts the performance by 25%. Is it worth it to run the 3.0V CR123A Li-ion battery, while it handles 3.6V CR123A Li-ion battery just fine? It's up to you.