Fenix P3D 3xCR123A battery tube

been using a 3xCR123A battery tube with some P3D's that i own (both smooth and textured reflectors; both Q5 and non-Q5 emitters).

i really like the new tube. same length, essentially, as a 2xAA L2D-CE tube. so, for my tastes, about as long a tube as i would want to pocket/EDC on a Fenix.

it should really increase the burn time i expect.

there is one phenomenon i noticed with the several P3D heads i tried.

perhaps the batteries were to blame??? don't know.

used three new Tenergy CR123A's in the new tube and used two older, slightly used Duracells in the original P3D tubes. this would favor, perhaps, the newer Tenergy batts, but the side-by-side tests reveal otherwise.

performed a side-by-side visual test (no light meter - sorry).

compared two Fenix at a time, side-by-side in a dark basement room with with white walls (never owned a camera, so, again sorry, no pics).

switched each head from the original tube to the 3xCR123A tube. kept it's tailcap switch with the head - whether on original tube or 3xCR123A tube.

in ALL cases/comparisons (Q5 v. Q5, non-Q5 v. non-Q5, smooth v. smooth, textured v. textured) the light was brighter (compared only the LOWEST output level) when the head was run on the original 2xCR123A P3D tube than it was on the 3xCR123A tube. the differences were very slight and barely noticeable in some cases, but more noticeable in others.

to illustrate: let's call one light A and the other B. A starts out on the original P3D tube and B on the 3xCR123A tube. A is brighter (on the lowest output setting) than B. Now, placed A on the 3xCR123A tube and B on its original tube (NOT the same original tube A started out on). B is now brighter than A. [Note: tailcaps followed heads]

i repeated this test for all possible, similar combinations (e.g., two Q5 smooth, two Q5 textured, two non-Q5 smooth, two non-Q5 textured, i.e. two lights compared at a time, even if 3 of one combination were in my possession).

in ALL cases the heads were brighter, on the lowest output levels on their original tubes.

at higher light levels, they seemed the same to my eyes - they're all just so bright at ~20' (the distance employed in this side-by-side test) indoors with white walls.

seems like, when run on a higher voltage, the buck converter might be "dialing" back the current just a bit for the lowest output mode??? don't know.

basically, i just like to know if anyone else has noticed something similar. light meter results would sure be more telling here - i would imagine. anyone have any thoughts on the reasons for what i observed? would appreciate being educated by someone on this point.

in my case, i'm still very pleased with the 3xCR123A tube and would recommend it as an upgrade to anyone's P3D. haven't yet determined burn-times on the 3xCR123A's, but it probably allows me to run on 50/53lumen output when i'm out and about at night instead of the 9/12lumen output and still achieve adequate (for my purposes) burn-times - a very nice improvement indeed.

3 cells in a P3D?? when did this happen? i thought that it is maximum 6v? If so where does one procure one of these tubes?

4sevens has tested the head over 12v so there is no problem. 3 CR123 bodys here.

any info on the Q5 working with these? or what brightness levels are with the extra cell?

OR runtime?

techwg said:

any info on the Q5 working with these? or what brightness levels are with the extra cell?

OR runtime?

Click to expand...

I remember reading that it just gives more runtime, no extra brightness. I have considered getting one but $51 is a bit steep for just a tube.

i think i agree. its a bit large for my use, however it interests me, i could afford it since i only pay half your dollar i would pay £25, but still a new whole light would cost me £40, so yes its still not cheap is it.

Icspots is right, the 3 battery tube only adds runtime, not output. It would still be an excellent addition to an excellent light though, given that the 2 cell P3D is only 4.5 inches! The 3 cell setup would only be what, 5.5 inches?

Gunner12 said:

4sevens has tested the head over 12v so there is no problem. 3 CR123 bodys here.

Click to expand...

SWEEET!!!! by "over 12V" do you mean it will work with Rcr123s too?

Bushman5 said:

SWEEET!!!! by "over 12V" do you mean it will work with Rcr123s too?

Click to expand...

Don't know, I'd email Fenix-Store and ask if I were you.

I think he tested the head to 16v but I'm not sure.

Yes, tested to over 16V. 4sevens had a couple of 4-cell prototypes (I want one!) made as well at the time the 2 and 3-cell bodies were made.

ALSO noticed that lowest setting is slightly dimmer than regular P3D lowest setting... (probably means even MORE runtime than the extra cell would allow for... 96 hrs plus). This doesn't disappoint me as I have always felt that a lower low would be better for both runtime and saving night vision.

Thing that's really great about this body tube is that you can use up older cells or inferior ones that won't run the turbo setting anymore in a reg. P3D and the 3-cell version will still run turbo (probably due to the higher voltage.) I have a bunch of fake Panasonic cr123a's (the company's name is (something) "ELESTRIC" company, with electric spelled wrong) which I had trouble with in my P1D Q5 and also in running turbo in the P2D and P3D. These cells work great in the 3-cell... No, not brighter, but it's almost like it has some extra uumpf... (I know that is very unscientific, I would guess that due to the higher voltage the frequency is faster= less flicker for the subconscious to notice, but that's just a guess, maybe one of you guru's would back this up or dispel the myth.)

Anyway, my vote is money well spent.

No, it's not EDC size anymore. Use my P2D for that. However, with a lanyard looped around the wrist, the non-roll ring fits nicely in the base of the palm. I usually carry it like this with my index finger against the side of the head, and keeping the bezel just slightly turned off of turbo, run the lowest setting and then activate turbo intermittently by side-pressing the head when needed for throw/distance. ALL YOU MULTI-MODE and STROBE/SOS HATERS should consider using this method.

Anyway, I could carry this light for hours like this, and have when helping out scout leaders with camp trips. Very comfortable.

Many have said "no thanks" to the size of a potential 4-cell body, but like I said, there wouldn't be any expectation of a light that is an EDC anyway at this point. I'd love to get my hands on one.

So technically, the 3-cell should have a 96hr, 20hr, 7hr and 2.8hr runtime rating. Maybe even longer as each cell doesn't have to work as hard/put as much power per cell. What would the 4-cell be like?

BTW... the 3-cell light is less than 1/32" longer than the L2D... have to look really closely to see the difference.


Said all of this before in other threads, but in bits and pieces. First time I've put it all together as I thought the subject relevant.

Chevrofreak did a runtime test of a P3D CE Q5 with two and three cr123a's(primarys). It looks like the green line on the graph is mislabled and should read 3x cr123a's because in parent directory it refers to it as a 2cell vs. 3cell test.

Anyhow it shows ever so slightly less output with three batteries but much more runtime.

Link to runtime test

Tests of the P3D with primary vs. rechargable show slightly lower output with the rechargable(more voltage).

Link to primary/rechargable runtime test

Could it be some quirk of the P3D circuitry that more volts mean slightly less output??? :shrug:

Many thanks to Chevrofreak for his wonderful runtime charts. :rock::rock::rock:

it would really help me to know what the total height of the P3D with that 3 cell tube would be. that way i could calculate if it would fit in my pouch and be worth a spend or not.

techwg said:

it would really help me to know what the total height of the P3D with that 3 cell tube would be. that way i could calculate if it would fit in my pouch and be worth a spend or not.

Click to expand...

look at the specs for the L2D (2xAA). they are virtually the same size (less than 1/32" longer than L2D according to another Poster - read 2benlightened's entire Post = GREAT info there). so, if you can "pocket"/EDC a L2D, then the 3xCR123A is no problem.

actually, while i clip a NovaTac 120P to my pocket, i prefer to carry the P3D with 4-7's 3xCR123A upgrade tube "concealed" in my pocket (even though a mini-mag lite clip has been placed on that light). in fact, in some pants, the 3xCR123A works out better than the "stock" P3D 2xCR123A tube. How so???

so glad you asked that! well,...

i like the P3D to remain upright in the pocket - more comfortable for me that way. the standard P3D 2xCR123A tube is too short and the light falls over and lays sideways in the bottom of my pocket. in this position, i can notice that it is there (yeah,...you're right...too OCD!!) - a VERY MINOR matter to be sure. however, the 3xCR123A tube is long enough that the light must remain upright, or nearly so, and can't fall over and move sideways to the bottom of my pocket. in my case, i rarely feel the P3D-Q5 with 4-7's 3xCR123A tube in my pocket. but, i'm a bit o' a strange one at times, so YMMV.

clipping it to my ballcap brim is more problematic however, but still doable, as long as my head isn't moving about too much which cause the light to move about more easily due to its longer length. a homemade "JakStrap"-like headband solves this issue when head-mounting of the light is necessary for hands-free operation (see Fenix does indeed already make "headlamps", but that is a matter for another Thread).

many thanks to 2benlightened who confirmed a similar slightly lower-LOW with the P3D when used with the 7777's 3xCR123A upgrade tube. normally, a lower LOW is right up my alley, which is why my Novatac EDC-120P has it's initial turn on setting at 0.47 lumens. however, for non-to-semi-demanding nighttime trekking, i generally like around 15lumens output to make sure that i don't miss any trail blazes on unfamiliar trails (though 12lumen with a smooth reflector works 'ok' most of the time too). so, in this case a lower-LOW is not beneficial to me. for other task/proximity lighting uses, a lower-LOW is my preference too.