# TK30 or TK40



## Recharger (Nov 28, 2009)

Got batteries for both just want that WOW factor.


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## DimeRazorback (Nov 28, 2009)

Well I would rather having to recharge only 2 batteries over 8 anyday


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## almach1 (Nov 29, 2009)

I actually like the buly/maglight feel of the tk40 got some 200 lumen lights for situations where size is an issue.


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## Jackscrj (Nov 29, 2009)

TK40 definitely has the wow factor at 630 lumens max
tk30 tops out at 225
however the tk30 is more practical you really don't need a tk40 except for search and rescue

yes tk30 has same output as tk40 *i must have been thinking of a ta30*


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## supes (Nov 29, 2009)

The TK30 is capable of the same output as the TK40, but it needs both 18650 cells to match it. 1x18650 equals around half the output.


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## tolkaze (Nov 29, 2009)

I'm pretty sure the business end of the light is the same, it really depends on if you like skinny bodies with a bigger head, or a fatter body. I guess the TK30 has the advantage of being run on 1x 18650 or 2xCR123's with a shorter body for up to 370 lumens, or with the extension tube for maximum power



Jackscrj said:


> TK40 definitely has the wow factor at 630 lumens max
> tk30 tops out at 225
> however the tk30 is more practical you really don't need a tk40 except for search and rescue


 
I think you will find that the TK30 also has 630 Lumens max on 2 batteries


*



Performance using two 2500 mAh 18650 rechargeable batteries (with extension tube)

Click to expand...

*


> Searching Mode:
> Output A - 100 Lumens / 16 Hours
> Output B - 630 Lumens / 1.5 Hours ​



​


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## headophile (Nov 29, 2009)

just something to consider:

i had the chance to handle a big-head, thin-body solarforce mce flashlight in a store. the feel on the hand is very different from my tk40 which is a lot more balanced as opposed to being top-heavy. tk40's tailcap is a chunk of aluminum that effectively counterbalances the weight of the head. imo the tk40 will be more comfortable to carry for extended periods of time.


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## Rod911 (Nov 29, 2009)

Jackscrj said:


> TK40 definitely has the wow factor at 630 lumens max
> tk30 tops out at 225
> however the tk30 is more practical you really don't need a tk40 except for search and rescue


You're referring to the *TA*30 which has a max lumen output of 225. The *TK*30 on the other hand, has the same/similar head as the TK40. The only differences are the power source and UI.

Personally, I'd go with the TK30. As DimeRazorback pointed out, I prefer the simplicity of the one/two battery (18650) option the TK30 provides versus the TK40's 4/8 AA batteries. I also like TK30's twisty UI.


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## yellow (Nov 29, 2009)

wonder that most of You think a big, bulky, high weight light will be mor comfortable to use at extended periods.

Smaller, better to grip (less body diameter), less number of cells (and not that 2 strings of 4 in parallel)
TK30 or Jetbeam M1X sound much better - to me at least

... simply changing cells out in the nowhere is a big argument: bring 2 spares, or 8!


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## Swedpat (Nov 29, 2009)

Isn't that clear that TK30 will provide 370lm with 2xCR123 and 630lm with 4xCR123? Yes, I see that 630lm only is stated for 2x18650, but I think they actually have missed to mention performance with 4xCR123? 

Regards, Patric


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## Buckley (Nov 29, 2009)

The tie-breaker for me is the issue of parasitic drain: The TK40 has it; the TK30 doesn't.


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## berry580 (Nov 29, 2009)

extra weight will always weight one down. A non-center balanced light can always be held off-centered to take account of its weight distribution.


headophile said:


> just something to consider:
> 
> i had the chance to handle a big-head, thin-body solarforce mce flashlight in a store. the feel on the hand is very different from my tk40 which is a lot more balanced as opposed to being top-heavy. tk40's tailcap is a chunk of aluminum that effectively counterbalances the weight of the head. imo the tk40 will be more comfortable to carry for extended periods of time.


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## headophile (Nov 29, 2009)

berry580 said:


> extra weight will always weight one down. A non-center balanced light can always be held off-centered to take account of its weight distribution.



the weight and size of the tk40 are blown way out of proportion in this forum in my opinion. the tk40 on 4 cells pretty much weighs as much as the solarforce light, only with a much better balance so it actually feels lighter. it's smaller than a d-sized mag and much easier to put in a bag versus a long thin light. it's very comfortable to hold too (i'm 6'1" though with fingers that are proportional to my height so this might not be true for shorter guys with shorter fingers).


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## krash (Nov 29, 2009)

I went through the same decision making process as you tk40 vs tk30 and i went for the tk40 purely on looks. I think skinny lights with big heads look weird.


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## bill_n_opus (Nov 29, 2009)

Do us proud ... and buy both.


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## collo (Nov 29, 2009)

Depends whether you would rather carry a toffee apple or a hot dog..


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## berry580 (Nov 29, 2009)

collo said:


> Depends whether you would rather carry a toffee apple or a hot dog..


lol, nice analogy.


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## snala (Nov 29, 2009)

It says working voltage is 3-12v so 4 CR123's i guess would work? 4 RCR's maybe bad for it though?
Also wondered is it full power on 2 x RCR123's as well? Would be 2 x 3.7volts, same as 2 x 18650's? How would it know otherwise?


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## pseudoblue (Nov 29, 2009)

Hi, I have a TK40, and would get the TK30 if I could too  In the end it really depends on you, both offer similar output but different UI and battery config.

I managed to have a hands-on experience with the TK30 from a friend. It actually looks smaller than the pictures and cute too. Similar head diameter size as the TK40. Its single body tube is thick and knurling feels good, The tailcap is identical with the TA series but does not tail stand. The body tube extender is a smooth anondized type, no knurling though. The threads looked like they are squared, and changing into different sets of modes felt very smooth and quite easy too. The UI is not complicated at all once you understand how it works. Basically you can have 2 switchable modes at one time, but you can switch into different sets respectively by the smooth bezel twists. The beam for this light is also smooth, but has a small donut hole in the hostpot, even at about 5 meters. I doubt this would be a bother in any applicable situations, The TK40's beam however has no donut hole even at 1 meter.

From my experience, it's difficult to find a wow factor if you experience both. But I would say to consider TK30 because of it's configurable size (with or without extender, less or more runtime), and battery configuration. If you were to use the light everyday and for hours, it's easier to pop 1 or 2 Li-IONs into the charger and back in again, it is also easier to switch batteries if they are drained. Than to have managed 8x AAs all the time, also making sure each are close to matching cells. To add, the light is not that imbalanced at all, the head is a little heavier but it's just a small difference.

Are you looking at other MCE options?


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## jirik_cz (Nov 30, 2009)

snala said:


> It says working voltage is 3-12v so 4 CR123's i guess would work? 4 RCR's maybe bad for it though?
> Also wondered is it full power on 2 x RCR123's as well? Would be 2 x 3.7volts, same as 2 x 18650's? How would it know otherwise?



You can not use 4xRCR123. But it works with 2x RCR123 at full output pretty well


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## apontes (Nov 30, 2009)

Recharger said:


> Got batteries for both just want that WOW factor.



IMO, the WOW factor will be the same with either. The emitter and the reflector are the same.

The differences are in UI, batteries used and form factor.

Try them both, get the one you feel more confortable with. Or both. :devil:


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## headophile (Nov 30, 2009)

just to add another perspective. my non-flashaholic-but-engineer-of-sorts uncle was particularly impressed that the tk40 runs on aa batteries. i agree with the past couple of comments though. get both


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## Recharger (Nov 30, 2009)

If I bought both lights they would have to come with an apartment because I would need a place to live.!!


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## Disco-Dave (Nov 30, 2009)

Ive got the tk30 on the way hope it doesnt take to long although i was in the same position u r now wasnt sure what one i wanted, my main reason for choosing the tk30 is the batterys i prefer 1 or 2 over using the 8aa's


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## snala (Dec 1, 2009)

jirik_cz said:


> You can not use 4xRCR123. But it works with 2x RCR123 at full output pretty well


 
So just to clarify also, it will run fully regulated at the full 370 lumans on 1 18650 as well? Says 370 on 2x CR123's but doesn't say that just for 1 3.7v 18650? (just like doesn't say full 630 on 2xRCR123 either?).

I'm guessing under 6v it can do 370 and over it's 630 so.....
If it does the full 370 on 1 18650 for 1.75 hours i'm sold.


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## jirik_cz (Dec 1, 2009)

Yes, it is fully regulated with one 18650 battery.


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## HKJ (Dec 1, 2009)

jirik_cz said:


> Yes, it is fully regulated with one 18650 battery.



Because it is running the led at less than full power, Vf is lower, allowing regulation at lower voltage, on my TK30 it maintains regulation down to 3.5 volt when in low voltage mode. In high voltage mode (630 lumen) it needs 4.4 volt to maintain regulation.
High/low voltage are two distinct modes, that is selected, depending on battery voltage, when the light is switched on.

Also note that the light does not fully support 4xCR123, the low mode disappears.


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## snala (Dec 1, 2009)

Fantastic jirik_cz and HKJ. Exactly what I was wanting to know. Is there a review somewhere that i haven't seen, i.e the graph?
Over 1.5 hours on the 18650's on both levels is excellent.


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## Bubu (Dec 1, 2009)

Its funny, everyone else here says they rather the TK30 due to the batteries. I bought the TK40 because of the batteries too, because it uses commonly found AA's. 

When I was looking for a good light one of the things I wanted was to be able to use common easy to find batteries. I am trying to resist the temptation of buying more flashlights and becoming a flashaholic... 

If I was to buy a flashlight that uses anything else other than AA's then it would be the only device in my household that would require CR123 batteries.

I dont like the idea of going away for a few days camping or whatever with flat batteries and then unable to purchase them because they are not as common as AA's. Then you may aswell leave the flashlight at home then.

This does not appear to be an issue for Recharger since he has batteries for both but thats just my 2 cents worth.

I am happy with my decision on getting the TK40.


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## desertrat21 (Dec 1, 2009)

I decided to get both and don't regret it a bit. :naughty:


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## was.lost.but.now.found (Dec 1, 2009)

desertrat21 said:


> I decided to get both and don't regret it a bit. :naughty:


 
Nice pic!! One question, why does the reflector of the TK30 look cloudy compared to the TK40?


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## Locoboy5150 (Dec 1, 2009)

Bubu said:


> Its funny, everyone else here says they rather the TK30 due to the batteries. I bought the TK40 because of the batteries too, because it uses commonly found AA's.



The TK40's use of AA cells is a love it or hate it thing. I personally love it too because all of the high end electronics in my home use AA batteries.

One thing that I've noticed is that the members of CPF have just about every type of battery under the sun, so they can get anything regardless of its power requirements.


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## desertrat21 (Dec 1, 2009)

was.lost.but.now.found said:


> Nice pic!! One question, why does the reflector of the TK30 look cloudy compared to the TK40?


 
I put diffusing film over the lens and turned it into a "wall of light" light. :naughty:
On high it's like walking around on an slightly overcast day... crazy floody.


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## snala (Dec 1, 2009)

You mentioned some beamshots, maybe without the film on as a comparison to compare to the TK40, a while back?


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## desertrat21 (Dec 1, 2009)

snala said:


> You mentioned some beamshots, maybe without the film on as a comparison to compare to the TK40, a while back?


 
I haven't had a chance to edit/resize the images yet but the TK30's beam profile is identical to the TK40 as the emitter and reflector are the same in both units. My TK30 is slightly different in tint though... it's more neutral than the cooler TK40 (but I can't attribute that to anything but normal variances). I'll post some images when I get the chance. Thanks for reminding me. :thumbsup:


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## Recharger (Dec 1, 2009)

TK30 is on It's way, $118 shipped new.


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## LightOnAHill (Dec 1, 2009)

Recharger said:


> TK30 is on It's way, $118 shipped new.



where did you order from? thanks


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## Recharger (Dec 1, 2009)

eBay, best offer. Offered him $110 he turned it down I counter offered with $115 and he took it. New factory sealed.


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## Jackscrj (Dec 2, 2009)

Sorry about that mishap yes the tk30 is capable of same output 
i think i was thinking about a tk12 or something


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## madmook (Dec 2, 2009)

desertrat21 said:


> I put diffusing film over the lens and turned it into a "wall of light" light. :naughty:
> On high it's like walking around on an slightly overcast day... crazy floody.


 Where can I buy some of that?


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## krash (Dec 2, 2009)

desertrat21 said:


> I put diffusing film over the lens and turned it into a "wall of light" light. :naughty:
> On high it's like walking around on an slightly overcast day... crazy floody.



I would love to see some pics of this, sounds bloody fantastic !!


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## desertrat21 (Dec 2, 2009)

madmook said:


> Where can I buy some of that?


 
I use two main types...

1) Fellowes WriteRight - a static-cling PDA screen protector sold at most office supply stores. It's transparent but with some surface texture that diffuses a flashlight beam nicely. It's better IMO on smaller lights... especially those with beam artifacts you'd like to remove. It took the beam from one of my Surefire TIR optic lights from lopsided and annoying to beautiful.

2) Clear Contact Paper - this stuff is inexpensive, easy to put on/remove, and is what I have on the TK30 in my previously posted picture. It works great. It makes the TK30 into one of my favorite field lights.

I measure the face of the lens, adjust my trusty compass, draw a circle, cut it out, and apply to the lens. It's very easy and once you get proficient looks like a stock product.



krash said:


> I would love to see some pics of this, sounds bloody fantastic !!


 
I'll snap some photos tonight and post them here. If you like floody, I think you'll be impressed. :naughty:


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## madmook (Dec 2, 2009)

Much thanks! I've ordered one of these: http://www.amazon.com/exec/obidos/t...t_shr?_encoding=UTF8&m=ATVPDKIKX0DER&v=glance

Hope that'll work.


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## desertrat21 (Dec 3, 2009)

Here are the comparison shots between the stock TK40 and the TK30 with the Contact diffusing film. Each configuration has its purpose, but the film does a great job at eliminating the eyestrain that comes from following a spot around during prolonged use.











Here's the animated comparison:


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## krash (Dec 3, 2009)

Thanks very much for posting the beam shots! your diffusing film idea is brilliant! i love spread the beam creates with the film.... cant wait to get my tk40 so i can try it myself


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## was.lost.but.now.found (Dec 3, 2009)

Is the difference in tint due to the diffuser film or due to bid variations of the emitter? The TK30 actually looks significantly warmer. At any rate, nice pics again and thanks for posting.


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## desertrat21 (Dec 3, 2009)

was.lost.but.now.found said:


> Is the difference in tint due to the diffuser film or due to bid variations of the emitter? The TK30 actually looks significantly warmer. At any rate, nice pics again and thanks for posting.


 
My TK30 is warmer than my TK40 (I'm very happy with the tint of the emitter). I haven't noticed that the film has any affect on color but I haven't done a before/after shot with the same light to rule it out. If it has an effect it's minor. I had the film on my TK40 for a while and still had the impression it was cooler than the TK30.


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## headophile (Dec 3, 2009)

nice even flood on the tk30. the diffuser worked out pretty well


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## snala (Dec 3, 2009)

I went and bought a TK30 yesterday. I compared it with a TK40 before I left the dealer and the beams seemed exactly the same as you all said here. The TK40 was a lot heavier than the 30 though and much "fatter" obviously too. I want to use mine for biking and shooting so 1 inch tube is perfect hence the TK30 choice and the fact it will run at a higher 370 lumens with just one battery vs 277 for the 40. Using 1 18650 it's not much bigger or heavier than a TK11 but blows that away for output. With 2 cells it isn't overly unbalanced either, just move your hand back a bit to centre it. 
Also it has a much larger hotspot than any single emitter R2 equivalent which gives quite a wide strong spread the further away you go. 630 lumens is frankly insane! Mine has no donut hole effect either.
First impression was it's actually more throwy than I thought it would be after reading the floody references talked about here. Does have a wide spill but on 370 and especially 630 lumens it still goes a long way. Beam colour on mine is definitely warmer than a Q5 and R2 which I'm happy about too.
As desertrat showed above an optional (easy off and on) diffuser cover could be a good extra to have also.

Thanks for your info here guys, helped with the decision and this should keep me happy for quite a while.


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## DimeRazorback (Dec 3, 2009)

Great beamshots desertrat21!

:twothumbs


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## donas (Dec 3, 2009)

I am thinking about the TK30 for Law Enforcement work, is there a time limit for the use in turbo or max output mode, in reference to overheating? If so how long and what type of cool down?

What is the opinion of a flashlightaholic for my purpose....I want super bright and of course durable (rechargeable options). Thanks


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## AMD64Blondie (Dec 4, 2009)

*Fenix TK40 a good choice?*

I just bit the bullet,and ordered a Fenix TK40 from Brightguy.com.
Does anyone else own one of these lights,and if so,how is it?
(Good,bad,or so-so...)

Here's the light I ordered:
http://www.brightguy.com/products/Fenix_TK40_LED_Flashlight.php

Thanks,Mike


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## madmook (Dec 4, 2009)

*Re: Fenix TK40 a good choice?*

Er... if you wanted a keychain light, well then you failed miserably.

But if you wanted one of the brightest led lights than run on 4x/8x AA batteries, then it is a very good purchase.

I wouldn't recommended loading up with alkalines if you plan on using the max mode much... hope you have some good quality rechargeable NiMH AA's like Sanyo eneloops.


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## Burgess (Dec 4, 2009)

*Re: Fenix TK40 a good choice?*

Just strikes me as a question you'd wanna' ask BEFORE you order.




Please let us know what YOU think of yer' TK40, when it arrives.


Good Luck.


_


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## AMD64Blondie (Dec 4, 2009)

*Re: Fenix TK40 a good choice?*

I'm most likely going to run it off of alkaline AAs,as I'm not really a fan of rechargable batteries.(It's a long story.) Hopefully I can manage to get a ride(from Mom or Dad-I don't have my driver's license) out to Costco some time to pick up some 48-packs of Kirkland AA batteries.(I have enough AAs at the moment,but I'm just thinking ahead.)


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## jimmy1970 (Dec 4, 2009)

*Re: Fenix TK40 a good choice?*

The TK40 is an excellent light - it will most probably be smaller & lighter than you expect also - it's almost a 1D cell shorter than a 2D maglite!

James.....


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## AOBRICK (Dec 4, 2009)

*Re: Fenix TK40 a good choice?*

I really like mine. I'm a cop and I use it on a nightly basis. While I don't carry it on my duty belt all the time (I have a fenix t1 for that) I keep it in my patrol bag for the times I need a lot of light like during traffic stops.

The battery life is respectable and as much as a diehard CR123 fan as I am, its kinda nice to have cheap AAs to burn through.
I do not use rechargeables I just never liked rechargable batteries, I know of the great benifits but I just cant stand them (keeps me away from 18650s)

This light is durable, I bought it when it first came out and it has hit asphalt a few times while I was chasing people.
It has more than a few battle scars but is holding up as well as a MAG 2D would, if not better. 

Over all this light gets an A- rating the thing that keeps it from getting an A+ is the switch, its not recessed and when i get in and out of the cruiser it is easily switched on (blinded myself a few times).

It wow's the non flashaholic public and has been given the occasional kudos by other officers (till I tell them the price, cops are notoriously cheap).


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## KevinL (Dec 5, 2009)

desertrat21 said:


> I use two main types...
> 
> 1) Fellowes WriteRight - a static-cling PDA screen protector sold at most office supply stores. It's transparent but with some surface texture that diffuses a flashlight beam nicely. It's better IMO on smaller lights... especially those with beam artifacts you'd like to remove. It took the beam from one of my Surefire TIR optic lights from lopsided and annoying to beautiful.
> 
> ...




BRILLIANT......many thanks!! 

I have a need to diffuse a TK40 and a LD20 for use as video lights. Cameras are really, really good at picking up hotspots.


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## Techeon (Dec 5, 2009)

I bought both the TK30 and the TK40 and they are both great lights. As for overheating on high and turning off, hasn't happened yet. They will get so hot you can't hold them though. The only small improvement on the TK 30 I'd like is for it to tail stand, but that's just me. Build quality of both lights is excellent (which I've grown to expect from Fenix) and the battery carrier quality in the TK40 is unbelievably good compared to other rigs. My recommendation is get both lights :twothumbs


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## Swedpat (Dec 5, 2009)

Techeon said:


> I bought both the TK30 and the TK40 and they are both great lights. As for overheating on high and turning off, hasn't happened yet. *They will get so hot you can't hold them though*. The only small improvement on the TK 30 I'd like is for it to tail stand, but that's just me. Build quality of both lights is excellent (which I've grown to expect from Fenix) and the battery carrier quality in the TK40 is unbelievably good compared to other rigs. My recommendation is get both lights :twothumbs



Really? I am waiting for a TK30 and have high expectations. My Maglite/Malkoff P7 never get that hot you can't hold it. Seldom a light is used long time continiously, for half an hour or more, however. 

Regards, Patric


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## ducat (Dec 5, 2009)

*Re: Fenix TK40 a good choice?*

An excellent light, I love mine, and use it all the time, but PLEASE get some rechargeables, they can withstand a greater current draw than alkalines, and are much better suited to the light when using turbo mode.
.


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## droeun (Dec 5, 2009)

*Re: Fenix TK40 a good choice?*

Do a search & you'll find tons of threads on it, lots of reviews too. I have one and it's great. Be careful with the batteries though, lots of people don't pay attention and screw up their lights. Not sure how well the alkalines will handle the current on turbo, but hope yours doesn't start leaking


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## John_Galt (Dec 5, 2009)

*Re: Fenix TK40 a good choice?*

Don't do alkalines! You won't even have to wait to see them leak from turbo mode. There was a thread a while back where a guy had a set of 8 Duracell alkalines leak from the parasitic drain of the light, after only a few days. Invest in a rechargeable system. A set of 8 Eneloops and a decent smart charger won't cost you more than $50-70. And that extra investment is a much better cost than having to replace a $150 light.


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## AMD64Blondie (Dec 5, 2009)

*Re: Fenix TK40 a good choice?*

What would be the best (simple) charger option?
(I'd perfer not to pay too much,as I just spent a total of $164.40 on my new Fenix TK40.)

I had a charger for my Mag85(may it RIP) but I could never figure out how to charge the batteries.

Would it be safe to test the light initally on alkaline AAs?


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## brianch (Dec 5, 2009)

*Re: Fenix TK40 a good choice?*

It will work with Alkalines. It just won't last very long or won't be as bright as it could possible be. I prefer the Sanyo Eneloops. Check Costco, here in Canada they have the batts and charger on sale. Not sure if it's the same in the states but its worth a shot. 

The TK40 is a great light. I had one not long ago but it broke when I dropped it from the top of a tree (long story). Getting ready to order the TK30 =)


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## brianch (Dec 5, 2009)

Now we just need a torture test on the TK30 :devil:


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## haydoncandlepower (Dec 5, 2009)

*TK30 - Protected vs unprotected cells?*

Does the TK30 allow you to use unprotected cells?

Does it cut out at something like 2.5 volts per cell?

I've managed to avoid protected cells so far and would like to keep it that way.


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## flasherByNight (Dec 6, 2009)

Anyone have a satellite dish?
I was thinking those small plastic covers that often ship to cover up the LNB's ought to be around the proper size.

I personally wouldn't want to have a "permanent" diffuser, but something I could pop on and off would be great!

(If the cap _were_ to fit, it would probably need to be sanded down to increase light transmission)


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## AMD64Blondie (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*

Question:will using fully charged Eneloops (hot off of the charger,no rest time),overload the LED? (Reason I ask is,I used to have a 3-D-cell based Mag85 -running 9 Sanyo NiMH AAs- and instaflashing the bulb was alwas a worry of mine).


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## Long RunTime (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*



AMD64Blondie said:


> Question:will using fully charged Eneloops (hot off of the charger,no rest time),overload the LED? (Reason I ask is,I used to have a 3-D-cell based Mag85 -running 9 Sanyo NiMH AAs- and instaflashing the bulb was alwas a worry of mine).



No, it's O.K..
Eneloops=1.2V
Alkaline=1.5V


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## Patriot (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*



AMD64Blondie said:


> Question:will using fully charged Eneloops (hot off of the charger,no rest time),overload the LED? (Reason I ask is,I used to have a 3-D-cell based Mag85 -running 9 Sanyo NiMH AAs- and instaflashing the bulb was alwas a worry of mine).




Eneloops would be ideal for the TK40. Whatever you do don't waste your time with alkie's. There's boat loads of info on the TK40 as well if you'd like to learn more detail about it through thread searching.


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## vintagebob (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*

I have two TK 40s! I love this flashlight.

But...

PLEASE get a set (or two) of rechargeable eneloops for this baby. You'll be doing yourself a BIG favor and the flashlight will appreciate it as well. The thought of burning through all of those alkaline batteries makes me cringe.


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## krash (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*

I also have this torch and bought a set of eneloops. These batteries are great are also will save you lots of money in the long run.


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## Gunner12 (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*

The light (along with most good LED lights) has a driver to raise or lower the voltage to what the LED needs(3-3.7v depending on the LED and driver current). NiMh AA batteries are 1.4-1.5v fully charged and can take a lot more current before sagging in voltage then alkaline batteries (also why your Mag85 poofed).


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## AMD64Blondie (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*

Here's the charger and NiMH AAs I just ordered:
http://www.batteryjunction.com/8800.html 

Titanium Smart Fast 8-Bay Charger AA/AAA model M8800.

Batteries: 
http://www.batteryjunction.com/eneloop-aa-4-pack-nimh-lsd.html

2 4-packs of Sanyo Eneloop 2000 mAh AAs.


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## Burgess (Dec 6, 2009)

*Re: Fenix TK40 a good choice?*

to AMD64Blondie --


Welcome to the wonderful world of *Guilt-Free Lumens* !


:wave:
_


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## Locoboy5150 (Dec 7, 2009)

*Re: Fenix TK40 a good choice?*

That's the exact same charger and battery set up that I bought for my TK40 and it works great. I love my TK40 and I don't regret buying it one bit. I'm sure that you'll feel the same way, but please post your opinions here when you get the chance to fire it up with the Eneloops.

One disadvantage to having a TK40 at least for me is that it has spoiled me as far as LED flashlights go. So far there is not one other LED light on the market that comes as close to satisfying all my needs.


----------



## sqchram (Dec 7, 2009)

*Re: Fenix TK40 a good choice?*

Terrible choice, you'd better send it to me right away!


----------



## drb46 (Dec 7, 2009)

*Similar Lights to TK40*

What lights would you suggest that I look at as an alternative to the TK40? I like the TK40, but I'm not sure about the 8 batteries. So maybe something with the same output, but different battery setup?


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## Disco-Dave (Dec 7, 2009)

Just collected my tk30 today what a light it is, straight to work after i picked it up out some fresh 18650's in it and at first it didnt seem that bright indoors but when i took it outside as its pitch dark already wow. I love it.

Found the UI pretty easy also just gota twist that head fast enough lol. I was suprised at how usefel the 12 lumen mode will actually be camping or doing wotever else when u dont need alot of brightness.

Ill get some beamshots tomorow night comparing the fenix tk30 with my dereelight dbs v3 3sm cree mc-e-m 

Anyone know how these would actually compete as i dont have both on me at the moment and dont have the slightest clue how much lumens the dbs puts out.

It is run on 2 18650's also and has the op reflector.


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## Disco-Dave (Dec 7, 2009)

*Re: Similar Lights to TK40*

tk30 its excellent i got mine today and love it, Its supposed to be the same output and beam maybe a slightly different tint and runs on 2 18650's.

Easy enough to change between modes and excellent output from 12 lumens to 630 lumens. Not sure if thats out the front lumens tho but great light anyway.


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## orbspeed1 (Dec 7, 2009)

deleted entry


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## was.lost.but.now.found (Dec 7, 2009)

*TK40 accessories*

Did anyone else notice that the Fenix 2009 Product Catalog listed a holster and lanyard as included accessories for the TK40?

Link here:

http://www.fenixlight.com.cn/download/download003.zip

Was this just lost in translation or are these features to be included in the future?


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## was.lost.but.now.found (Dec 7, 2009)

*Re: Similar Lights to TK40*



drb46 said:


> What lights would you suggest that I look at as an alternative to the TK40? I like the TK40, but I'm not sure about the 8 batteries. So maybe something with the same output, but different battery setup?


 
You mentioned you are unsure. If you'd still consider it, I can tell you in my experience that loading 8 batteries in the battery magazine of the TK40 is not as arduous as some might like you to believe.


----------



## Gunner12 (Dec 7, 2009)

*Re: Similar Lights to TK40*

Do you want a quad die or large die light similar in size and shape to the TK40?

What types of batteries do you prefer?

Look at the Neofab Legion II and the Olight M30.

:welcome:


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## Saint_Dogbert (Dec 7, 2009)

*Re: TK40 accessories*

Given this is the 2009 catalog, showing lights which have already been updated, I would say it is a misprint/translation error. Never heard of a TK40 shipping with a holster, or even a traditional lanyard.


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## Locoboy5150 (Dec 7, 2009)

*Re: Similar Lights to TK40*



drb46 said:


> What lights would you suggest that I look at as an alternative to the TK40? I like the TK40, but I'm not sure about the 8 batteries. So maybe something with the same output, but different battery setup?



That's one of the things that I like about the TK40, it doesn't have to use 8 batteries. It also fully operates in all output modes with just 4 AA cells.

If you're looking for the same TK40 output with a different battery set up, look no further than the Fenix TK30.


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## supes (Dec 7, 2009)

*Re: Similar Lights to TK40*

You guys with both(TK40 and TK30), is the reflector size the same for both?

I see a noticeable hole in the center beam at close ranges in my TK30. The collar metal area where you twist to change modes looks like it could be thicker.


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## Rich_T23 (Dec 7, 2009)

Ive just ordered a fenix TK40 to replace my 5 year old standard ( as it was when it came out of the packet) 2 D cell maglite.
it will be interesting to see if it (TK40) lives up to the hype.


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## supes (Dec 7, 2009)

I'm quite positive you will be impressed vs your 2D [email protected] You might even get a bit of a grin on your face when you turn it on Max.


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## drb46 (Dec 7, 2009)

*Re: Similar Lights to TK40*



Gunner12 said:


> Do you want a quad die or large die light similar in size and shape to the TK40?
> 
> What types of batteries do you prefer?
> 
> ...



Well, I looked at them and now I want all three!


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## Disco-Dave (Dec 7, 2009)

Rich_T23 said:


> Ive just ordered a fenix TK40 to replace my 5 year old standard ( as it was when it came out of the packet) 2 D cell maglite.
> it will be interesting to see if it (TK40) lives up to the hype.



Youll be happy lol, the boss of my security firm turned up lastweek at a construction site i was on and went a patrol round it with me its pitch dark he pulled out a 4d cell maglite a black one i had my tk11 r2 shoulda seen his face lol. His Words were ****sake

Only wish i has my tk30 at the time.


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## Sardaukar (Dec 8, 2009)

I prefer the form factor of the TK30. Also not a fan of 8xAAs.


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## almaujo (Dec 8, 2009)

*TK30 v TK40 - extreme cold weather*

Thinking about getting one of these two. As I would be using it at times in extreme cold (-40 or below as I live in the Yukon) it would seem that the TK30's ability to use lithium CR123A batteries would make it superior in this regard. But would I be right in assuming that a TK30 with rechargeable Lithium-Ion 18650s would outperform the TK40 with AA eneloops in extreme cold?


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## AMD64Blondie (Dec 10, 2009)

Oh great... my new Titanium M8800 Smart Fast 8 Bay AA/AAA Battery Charger,and my 8 new Eneloop AAs arrived today..but,my Fenix TK40 isn't scheduled for delivery until tomorrow. Aaagh!! The waiting is agonizing!!


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## Burgess (Dec 10, 2009)

Hey, no problem . . . .

You DO realize those Eneloops are only ~2/3rds charged
when they ship from the factory, don't you ?

(if you didn't know it, then you haven't been doing enough reading on CPF) 

Here is yer' Golden Opportunity to get those batteries to 100 %,
in preparation for the Maiden Voyage of your new Fenix.


Hope you enjoy the new stuff. Please let us know what you think.

Good Luck.


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## AMD64Blondie (Dec 10, 2009)

Question: how long do I need to charge my new Eneloops to bring them up to 100% capacity?

Thanks,Mike


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## Burgess (Dec 10, 2009)

Afraid i'm not familiar with your battery charger.

I use the Maha 9000 model (4-bay)


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## Locoboy5150 (Dec 10, 2009)

AMD64Blondie said:


> Question: how long do I need to charge my new Eneloops to bring them up to 100% capacity?



To play it safe, I would use the refresh function on your Titanium Innovations M8800 charger on your new Eneloops. That will discharge them down to about 1.15 volts first. The discharging should take about four to five hours. Then the charger will automatically start charging the batteries again.

The reason why I suggested discharging your batteries with the refresh function first instead of just charging them up immediately is because I read in a thread here that battery chargers that use negative delta voltage to determine when to stop charging can overcharge batteries if the batteries are not first drained to a certain level. I don't know what that level is, but I suggest discharging your batteries first just to make sure that they're not overcharged because the Titanium Innovations charger uses negative delta voltage to sense when the batteries have peaked. I've also heard about people overcharging their brand new batteries as well, so better to play it safe in my opinion.

I just used the refresh function on my Titanium Innovations M8800 charger today for the very first time and it works as described in the instruction manual. I started discharging the cells at 11:00 AM this morning. As I type this at 3:00 PM, six of the cells went into charge mode and two of them are still discharging.

If you want to stop the discharging process early and start charging, just press the refresh buttons as the cells are being discharged.


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## Locoboy5150 (Dec 10, 2009)

AMD64Blondie,

Take a look at today's replies to your thread titled "Do Eneloops Come Precharged" in the Flashlight Electronics forum. They pretty much say exactly what I mentioned in my reply above.

Be careful on those first few charge cycles on your new batteries!

Also, it's now 3:30 PM as I type this and now all 8 of my Eneloop batteries are in the charge mode and I didn't have to touch anything on my charger. My Titanium Innovations M8800 is working exactly as it should.


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## AMD64Blondie (Dec 11, 2009)

I just received my new Fenix TK40. Opened the package up,peeled my new wonder out... and after installing my new Eneloop AA batteries,did something very dumb.(Three Stooges-esque...) I went into my bathroom,turned off the overhead lights,closed the door...and flipped my TK40 on for the first time.(Unknowingly,I had set it on Turbo-630 lumens- by mistake).OW! MY EYES!!! That was fun... 
I haven't charged my new Eneloops yet.(I'll probably wait until tomorrow to charge them.I'm having way too much fun right now..)


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## Lightcrazycanuck (Dec 11, 2009)

collo said:


> Depends whether you would rather carry a toffee apple or a hot dog..


 
lovecpflovecpflovecpf


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## Locoboy5150 (Dec 11, 2009)

AMD64Blondie said:


> I just received my new Fenix TK40.



Please post your thoughts and opinions after a weekend of fun with your new TK40.


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## Lightcrazycanuck (Dec 11, 2009)

Locoboy5150 said:


> Please post your thoughts and opinions after a weekend of fun with your new TK40.


 
+1


lovecpf


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## haydoncandlepower (Dec 12, 2009)

*Re: TK30 - Protected vs unprotected cells?*



haydoncandlepower said:


> Does the TK30 allow you to use unprotected cells?
> 
> Does it cut out at something like 2.5 volts per cell?
> 
> I've managed to avoid protected cells so far and would like to keep it that way.



Been a few days here. Nobody has an answer to this question? I guess no one is buying the TK30?


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## brianch (Dec 12, 2009)

AMD64Blondie said:


> I just received my new Fenix TK40. Opened the package up,peeled my new wonder out... and after installing my new Eneloop AA batteries,did something very dumb.(Three Stooges-esque...) I went into my bathroom,turned off the overhead lights,closed the door...and flipped my TK40 on for the first time.(Unknowingly,I had set it on Turbo-630 lumens- by mistake).OW! MY EYES!!! That was fun...
> I haven't charged my new Eneloops yet.(I'll probably wait until tomorrow to charge them.I'm having way too much fun right now..)


Don't worry my procedure for introducing new flashlights in my life is very similar. :duh2:


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## headophile (Dec 13, 2009)

*Re: TK30 - Protected vs unprotected cells?*



haydoncandlepower said:


> Been a few days here. Nobody has an answer to this question? I guess no one is buying the TK30?



or maybe no one is buying unprotected cells


----------



## brianch (Dec 13, 2009)

*Re: TK30 - Protected vs unprotected cells?*



haydoncandlepower said:


> Been a few days here. Nobody has an answer to this question? I guess no one is buying the TK30?


sorry I didn't even see your question. I use all my lights with unprotected cells. The TK30 works fine. A spacer is needed, but that is included with the light.


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## haydoncandlepower (Dec 13, 2009)

*Re: TK30 - Protected vs unprotected cells?*



brianch said:


> sorry I didn't even see your question. I use all my lights with unprotected cells. The TK30 works fine. A spacer is needed, but that is included with the light.


Thanks. No problems over discharging the cells? The runtime chart I saw posted makes it seem like the light sort of "turns off" at the end. But it was using protected cells so it might be the cells that were responsible for that. :-/


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## uknewbie (Dec 14, 2009)

I thought the TK30 looked like a better option over the TK40, given that it uses only 2 cells over 8 and has the added benefit of being that bit slimmer becuase of it, with the same output and head size.

Can someone explain why the runtimes are so similar? I know the TK40 is listed with better runtimes, but not by very much. Not getting 3x as much on any mode. 

TK40 @ 630 lumens = 2 hours
TK30 @ 630 lumens = 1.5 hours

TK40 is 33% increase.

TK40 @ 13 lumens = 150 hours
TK30 @ 12 lumens = 90 hours

TK40 is 66% increase.

However:

_TK40 - 8 x 2000 mAh AA = 16Ah
TK30 - 2 x 2500 mAh 18650 = 5Ah

TK40 has 220% increase in capacity.

Right?_

Or am I missing something painfully obvious  What is the point in all those extra batteries?

Some serious extra runtime would make me put up with the addidtional batteries and size, but still more tempted to get a TK30 as is.


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## HKJ (Dec 14, 2009)

uknewbie said:


> _TK40 - 8 x 2000 mAh AA = 16Ah
> TK30 - 2 x 2500 mAh 18650 = 5Ah
> 
> TK40 has 220% increase in capacity.
> ...



You are missing the voltage, LiIon is around 3 times the voltage of NiMH, a better calculation would be:

_TK40 - 8 x 2000 mAh x 1.2 volt AA = 19.2 Wh
TK30 - 2 x 2200 mAh x 3.6 volt 18650 = 15.8 Wh
_


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## Swedpat (Dec 14, 2009)

HKJ said:


> You are missing the voltage, LiIon is around 3 times the voltage of NiMH, a better calculation would be:
> 
> _TK40 - 8 x 2000 mAh x 1.2 volt AA = 19.2 Wh
> TK30 - 2 x 2200 mAh x 3.6 volt 18650 = 15.8 Wh
> _



Calculating with two CR123 cells the total amount of energy is higher than one 18650, but 18650 provides longer runtime, though. Of some reason the efficiency is higher with 18650 cells than CR123. I guess it's the same with 2x18650 and 4xCR123, any explanation of this?

Regards, Patric


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## uknewbie (Dec 14, 2009)

HKJ said:


> You are missing the voltage, LiIon is around 3 times the voltage of NiMH, a better calculation would be:
> 
> _TK40 - 8 x 2000 mAh x 1.2 volt AA = 19.2 Wh
> TK30 - 2 x 2200 mAh x 3.6 volt 18650 = 15.8 Wh
> _




So does the above relate to the amount of power available then, which would be a 21.5% increase? If so, how can, with the same LED, a runtime increase of over 60% be acheived?

Wish I had pain some attention in high school...


So the only advantage of the TK40 is the extended runtimes, which you get at the expense of bigger body, and more cells?

Seems to me the TK40 is there purely for people who want to be able to walk into pretty much any shop and buy batteries for their torch.

This notion doesn’t appeal to me and I would hate to be buying AA's using them and then throwing them away eight at a time. Seems to make more sense to have two cells that I can re-charge.

TK30 I think. Unless I waver towards the Jetbeam M1X, which I think looks great.


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## HKJ (Dec 14, 2009)

uknewbie said:


> Which begs some more questions of how can they manage runtime increases of over 60% with inly a 21.5% increase in power?



My calculation are not exact, the actual energy contents depend on how hard the cells are loaded. If you search around on cpf you can find some more exact measurements of energy contents at different loads for different types of cells.



uknewbie said:


> So the only advantage of the TK40 is the extended runtimes, which you get at the expense of bigger body, and more cells?
> 
> Seems to me the TK40 is there purely for people who want to be able to walk into pretty much any shop and buy batteries for their torch.



Do not forget the ui, the TK30 has the (extended) tactical interface, where TK40 has a much more elaborate interface.




uknewbie said:


> TK30 I think. Unless I waver towards the Jetbeam M1X, which I think looks great.



M1X is another type of light, much more throwy, then you need to compare to ThruNite Catapult.


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## HKJ (Dec 14, 2009)

Swedpat said:


> Calculating with two CR123 cells the total amount of energy is higher than one 18650, but 18650 provides longer runtime, though. Of some reason the efficiency is higher with 18650 cells than CR123. I guess it's the same with 2x18650 and 4xCR123, any explanation of this?
> 
> Regards, Patric



The usual problem with one 18650, is that the light goes out of regulation before the cell is empty, the will reduce the power consumption and give longer runtime. Two CR123 will stay in regulation and has full power consumption, until the batteries are empty.


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## Swedpat (Dec 14, 2009)

HKJ said:


> The usual problem with one 18650, is that the light goes out of regulation before the cell is empty, the will reduce the power consumption and give longer runtime. Two CR123 will stay in regulation and has full power consumption, until the batteries are empty.



Thanks,

I see now that my calculation is based of a 2200mAh 18650 cell. Using 2500mAh (as Fenix example) the total energy amount is almost exactly the same as two CR123 cells. 
When Fenix states: *

Performance using two 2500 mAh 18650 rechargeable batteries (with extension tube)
**Output B - 630 Lumens / 1.5 Hours*

Does this mean that these 1,5 hours are not fully regulated, but 4xCR123 will provide fully regulated 630lumens but for slightly shorter time? 

Regards, Patric


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## Magnumpy (Dec 14, 2009)

uknewbie said:


> This notion doesn’t appeal to me and I would hate to be buying AA's using them and then throwing them away eight at a time. Seems to make more sense to have two cells that I can re-charge



their are rechargeable AA batteries commonly available, you know...


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## HKJ (Dec 14, 2009)

Swedpat said:


> When Fenix states: *
> 
> Performance using two 2500 mAh 18650 rechargeable batteries (with extension tube)
> **Output B - 630 Lumens / 1.5 Hours*
> ...



Two 18650 will be regulated, and TK30 does also regulate fairly well with a single 18650, because it uses a lower output.


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## uknewbie (Dec 14, 2009)

Magnumpy said:


> their are rechargeable AA batteries commonly available, you know...



Of course.

I just don't see why someone would chose to re-charge 8 cells instead of 2?


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## desertrat21 (Dec 14, 2009)

uknewbie said:


> Of course.
> 
> I just don't see why someone would chose to re-charge 8 cells instead of 2?


 
In a pinch/emergency the TK40 still renders itself operable on commonly available cells... 18650's are great only if you've got electricity and a charger.

Both lights have their place... that's why I bought both. :naughty:

I mosty use the TK30 but it's nice to have an option.


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## was.lost.but.now.found (Dec 14, 2009)

uknewbie said:


> Of course.
> 
> I just don't see why someone would chose to re-charge 8 cells instead of 2?


 
Because I have 16 NIMH AAs and two AA chargers, and zero 18650s and zero li-ion chargers. I also have many more alkaline AAs that can be used in a pinch. It's actually pretty simple when you look at it that way.


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## Locoboy5150 (Dec 14, 2009)

was.lost.but.now.found said:


> Because I have 16 NIMH AAs and two AA chargers, and zero 18650s and zero li-ion chargers. I also have many more alkaline AAs that can be used in a pinch. It's actually pretty simple when you look at it that way.



Yep, makes perfect sense to me too and it's AA power source was the main selling point for my TK40 purchase...and I don't regret it one single bit!  I have a large 8 cell charger than can handle the TK40's power source without any problem.

Also, and this was what really sealed the deal for me buying my TK40, all of my expensive Nikon camera equipment use only AA cells. Thus, I have lots of Duraloop/Eneloop AA cells for everything. When I travel, as far as electronics go, I only take two things with me, my Nikon camera equipment and my flashlights. 100% all of them take AA batteries, so all I need are some spare Duraloops/Eneloops and I'm all set. I don't have to pack any special or different batteries whatsoever.

What really sold me on AA cells was my first ever trip out of the US last year. In China I couldn't find any of the more flashlight specific types of batteries like CR123, 18650, 18670, etcetera, but AA cells were everywhere.

I don't know if my logic makes any sense, but if not then all I can say is that the TK40 works absolutely *perfectly* for me and I have zero complaints or regrets with my purchase and my reasoning behind my purchase. If anyone *still* doesn't "get" my reasoning, then you'll probably never get it, but that's perfectly OK because there are plenty of choices for you starting with none other than the subject of this very thread, the Fenix TK30. 

Simply put, I love AA cells!


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## Locoboy5150 (Dec 14, 2009)

I forgot to add that just because the TK40 has room for 8 AA cells, which seems like a lot to some people, that doesn't mean that you have to use 8 cells in it. It operates perfectly in all modes with just 4 AA cells too. There is no decrease in light output when using just 4 batteries.


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## NewbieBill (Dec 14, 2009)

Fenix recommends not using turbo with 4 batteries for fear you may damage the cells.


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## Locoboy5150 (Dec 14, 2009)

NewbieBill said:


> Fenix recommends not using turbo with 4 batteries for fear you may damage the cells.



That's true. I have to admit that I've only used my TK40 on turbo mode with only 4 batteries for about 5 minutes at a time.


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## headophile (Dec 15, 2009)

NewbieBill said:


> Fenix recommends not using turbo with 4 batteries for fear you may damage the cells.



that only pertains to alkaline primaries. eneloops can handle loads 3 times as high as a tk40 on turbo :thumbsup:


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## compasillo (Feb 21, 2010)

desertrat21 said:


> Here are the comparison shots between the stock TK40 and the TK30 with the Contact diffusing film. Each configuration has its purpose, but the film does a great job at eliminating the eyestrain that comes from following a spot around during prolonged use.
> 
> 
> 
> ...



First of all: thanks a lot to *desertrat21* for your contribution. 
That "simple" trick has helped me a lot improving some dirty beam (low quality/defective reflectors) flashlights I was keeping apart in my collection.
Tried a few kind of diffusing films and found out a new world of possibilities.
Really amazing how a little piece of film can solve problems.
It's very easy to get a warm / neutral white beam just applying the right film to the lens. I've got effects as pure flood, several warm tint degrees and different diffused spots. And this is only my first trial day. 

(Kaichu Dento - the King of the warm tint - would be very happy trying this).

Back to the topic. For the last week I've been trying to decide the OP question: TK30 or TK40?
Now I think I'll get the TK30: form factor, batteries simplicity & versatility, weight...
One thing I would change: as they have their gravity point near the head I would prefer a side clicky switch.


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## Locoboy5150 (Feb 23, 2010)

compasillo said:


> One thing I would change: as they have their gravity point near the head I would prefer a side clicky switch.



The upcoming TK45 will have a side switch so it might be worth waiting for before you buy a TK30.

...just food for thought.


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## CM2010 (Apr 20, 2010)

With the TK30 using CR123`s do you get the full 630 lumens running 4 of them with the extension tube fitted?


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## Bullet120 (Apr 20, 2010)

The manual gives performance and runtime for 2x123 or 1x18650 stating runtimes longer with 18650 but only gives advertised output and runtime for 2 x18650. Does not address 4 x 123. My assumption would have to be it is less. I'm sure someone with detailed knowledge where this light regulates itself could specify.


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## HKJ (Apr 20, 2010)

CM2010 said:


> With the TK30 using CR123`s do you get the full 630 lumens running 4 of them with the extension tube fitted?



Yes, you get full output, but looses the low mode.


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## slicey (May 22, 2010)

HKJ said:


> You are missing the voltage, LiIon is around 3 times the voltage of NiMH, a better calculation would be:
> 
> _TK40 - 8 x 2000 mAh x 1.2 volt AA = 19.2 Wh_
> _TK30 - 2 x 2200 mAh x 3.6 volt 18650 = 15.8 Wh_


 
Your answer is correct, however, the formula for calculating Wh is:
V x I = Watt hours

so (8 x 1.2 volt AA) x 2 Amp hours = 19.2 Watt hours


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## petersmith6 (May 22, 2010)

ive got the TK30 ,i was going to get the TK40 as 18650 are some what scarce in england...but im glad i picked up the TK30,mainly cos i can change the two 18650 in total darknes in about 30 seconds..lets see some one change 8 AA in a holder in total darknet with out putting them in the wrong way ,droping them or using a wide range of explitives


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## g.p. (Sep 28, 2010)

*Re: TK30 v TK40 - extreme cold weather*



almaujo said:


> Thinking about getting one of these two. As I would be using it at times in extreme cold (-40 or below as I live in the Yukon) it would seem that the TK30's ability to use lithium CR123A batteries would make it superior in this regard. But would I be right in assuming that a TK30 with rechargeable Lithium-Ion 18650s would outperform the TK40 with AA eneloops in extreme cold?


I'm in the same boat up here in northern Canada. Anybody have real world experience and can offer an opinion?


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## recDNA (Sep 28, 2010)

I love my TK40 but I'd be tempted to try an Olight M31.


----------



## jax (Oct 28, 2010)

*Re: TK30 v TK40 - extreme cold weather*



g.p. said:


> I'm in the same boat up here in northern Canada. Anybody have real world experience and can offer an opinion?


 i agree,i live in canada too,one night at -30 i was out in the woods for a few hours and alkalines just cant cut it,also i would like to see light manufactures state the operating temperature capablities...ie +40 to -40 ect... i noticed on the wolfeyes web site that they rate some of there lights for -15....not good enough,thats a warm winters day here..no sale
lith-ions for sure for any true northern outdoors man..


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## DM51 (Oct 28, 2010)

*Re: TK30 v TK40 - extreme cold weather*

The limiting factor in extreme cold conditions will be the batteries. Good lithium primaries will work down to -40 deg, by which time most other cells/chemistries will have given up. 

The light itself would probably work perfectly OK at lower temps than that, but if the batteries have frozen solid you won't have any way of telling.

I once spent some time in polar regions, and if we needed battery power for instruments we used umbilical cords to battery packs kept inside our clothing and therefore warmer than the outside temperature. The umbilical had to be made of silicone rubber, or it would freeze stiff and could snap quite easily.


----------



## tandem (Oct 29, 2010)

*Re: TK30 v TK40 - extreme cold weather*



jax said:


> i agree,i live in canada too,one night at -30 i was out in the woods for a few hours and alkalines just cant cut it



Chances are Eneloop rechargeables would have done substantially better than your alkaline cells. There is some evidence they'll outperform li-ion cells too, potentially making them an alternative or at least a fall back to lithium primaries for cold weather use.

Maybe not extreme cold weather use... but -30C isn't all that cold, only -22F! 

On cold weather NiMH performance there's a test here... and another discussion here.


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## bill_n_opus (Nov 1, 2010)

uknewbie said:


> Of course.
> 
> I just don't see why someone would chose to re-charge 8 cells instead of 2?


 
Hmmmnn ... I just don't see why someone would choose to buy a li-ion charger plus some 18650's ... when they already have NiMh chargers/batteries at their disposal and ready to go?

The way I see it is that i've already saved 35-40 bucks minimum ... and the tk40 is a fine light as it is.


----------

