# Jetbeam Jet-u and Fenix L0D-CE 1AAA shootout: RUNTIMES, BEAMSHOTS, and TEMPERATURES



## selfbuilt (Jul 9, 2007)

*Jetbeam Jet-µ and Fenix L0D-CE 1AAA shootout: RUNTIMES, BEAMSHOTS, and TEMPERATURES*

*The contenders*:

Fenix L0D-CE on left (bought at the Fenix-store.com several months ago, and my main EDC ever since), Jetbeam Jet-µ on the right (just received by air mail directly from JetBeam)






*Method:*

Home-made lightbox a la Quickbeam's FR.com method. My relative overall output numbers are typically similar to his, although generally a little lower. You can directly compare the runtime graphs - i.e. an output value of "10" in one graph is the same as "10" in another.

*Beamshots:*

The relative output can be a bit misleading, given how the Jet-µ is almost all flood and the L0D-CE is a traditional spot beam with spill. Believe it or not, my lightbox reports the Jet-µ is brighter in most modes (see runtimes below). Relative output differences were confirmed by the “ceiling bounce” test in a small window-less room. 

All beamshots below done on L92 Energizer e2 lithium batteries, at same exposure settings: 1/10sec exposure, F-stop 2.8, daylight white balance. Lights are about ~0.5M from the wall, to better show the spillbeams.

Low mode: L0D-CE on left, Jet-µ on right





Primary (medium) mode: L0D-CE on left, Jet-µ on right





Hi mode: L0D-CE on left, Jet-µ on right





*Runtimes:* 

All runtimes done in my lightbox under a cooling fan, with the identified batteries listed below.
















For Li-ion, I used a pair of AW 320mAh unprotected 10440s, sold in the Dealer’s forum with a Nano charger. 






For the 10440 Lo mode run, I very briefly stopped the run at 1 hour intervals to verify the voltage on the 10440s (both 4.17V to start), and then continued the runtimes. Note that it's dangerous to run these down as far as I did (i.e. 75% initial output). In practice, I'd never let a light go below ~3.65V, because it's a rapid voltage "ski-slope" down from there.






*Notes:*
*PWM:* The L0D-CE uses 100 Hz in primary and low, the Jet-µ uses 314 Hz in primary and low. The L0D-CE strobes at 8.3 Hz, the Jet-µ at 7.6 Hz. 
*Mode Sequence:* L0D-CE sequence is primary-low-hi-strobe-sos. The Jet-µ is primary-low-hi-strobe-standby. The Jet-µ also has a memory feature that memorizes the last mode used if you leave it in that mode for more than 1-2secs (a quick flash shows you memory is activated). When you turn the light back on, it will return to this last mode use (when the feature is working properly – see below for a discussion).
*Li-ion 10440 compatibility:* Although both lights can take 10440, running in Hi mode is not recommend for prolonged periods on either. In fact, _*the Jet-µ’s SSC emitter can’t last more than a few secs without turning bright blue (a sign of over-heating).*_ 

Here’s a few beamshots showing the Jet-µ on Hi on 10440 on the right, against my Surefire L2 on Hi on the left (all beamshots at 1/100sec exposure, F2.8, daylight white balance):

5 secs: L2 on left, Jet-µ on right





10secs: L2 on left, Jet-µ on right





15secs: L2 on left, Jet-µ on right





In real life, it doesn’t seem quite as blue as the images suggest, but you can tell it’s pretty bad!

I’ve done some temperature readings of the exterior surface of the head of the L0D-CE and Jet-u, both near the lens using a flexible temp probe taped down. No external cooling is applied for this test. Readings taken at 5sec intervals:






Frankly, I really risked destroying my Jet-µ emitter in the test above – WAY too blue after 45secs! And too hot to hold - very unpleasant unscrewing the head by hand above >50 C, let me tell you.

*Key observations:*


L0D-CE is a traditional spot/spill beam, whereas the Jet-µ is almost all flood. This gives the mistaken subjective impression the L0D-CE is brighter, when it fact my lightbox and “ceiling bounce” tests all confirm the Jet-µ is brighter in most modes on most batteries.
Overall build quality is generally good on both, although the threads on the Jet-µ are very small and narrow, being on the interior surface of the battery tubes (i.e. just like the JB C-LE). Along with the foam spacer to stop battery rattle, this can make it harder to reliably switch modes on the Jet-µ (especially single-handed)
The sequence and memory mode features of the Jet-µ only work if you keep the screw threads and all contacts *scrupulously* clean. A lot gunk quickly builds up in the threads of the Jet-µ, causing out-of-sequence errors, missed modes, forgotten memory, etc.
The L0D-CE seems to outperform in terms of runtime on all tests, but Jet-µ runtimes are still acceptable, especially considering its typically higher output.
10440 batteries cannot safely be used on Hi in the Jet-µ without risking serious damage to emitter very quickly. Of course, 10440 on Hi is not recommended on the L0D-CE either, as thermal runaway could occur without you even realizing it (i.e. no tint-shift occurs on the Cree). The Jet-µ also quickly becomes too hot to hold, much faster than the L0D-CE does in this mode.
I didn’t see any tint-shifting on 10440 in primary (medium) mode on the Jet-µ during runtime tests, but those tests were done under a cooling fan
10440 on Lo is the one time the Jet-µ exceeded the runtime of the L0D-CE for an equivalent output
*Jet-µ Conclusions*

*Pros :*

One of the floodiest beams I’ve seen (good for a keychain EDC, in my opinion)
Uses higher PWM freq, so less “flicker” noticeable
Standby (i.e. beacon) likely more useful than SOS 
Memory mode good idea if you want to insure light comes on in certain state, but may need to cycle through strobe/standby to get back to earlier modes
Blue-tint shifting of SSC good indicator if over-heating occurs
Ability to run 10440, and more efficiently in Lo mode than the L0D-CE. But Hi on 10440 does not seem feasible for any amount of time on the Jet-µ (of course, I personally don't recommend Hi mode on the L0D-CE either)
*Cons:*

Floody beam gives subjective impression of being dimmer than it actually is
Screw threads have relatively poor feel and greater tension, making it difficult to reliably shift modes. 
Threads get dirty quickly, leading to out-of-sequence errors and forgotten memory mode (similar problem to the new v1.2 C-LE). Maintenance level is thus higher than the L0D-CE
Runtime lower than L0D-CE in almost all tests of various modes on various batteries - although with typically higher output of the Jet-µ
Poor heatsinking compared to L0D-CE, as evidenced in 10440 Hi mode tests

As always, your call what suits you best. Cheers!
:twothumbs


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## mchlwise (Jul 9, 2007)

EXCELLENT comparison and review. :twothumbs

I've been very interested in this comparison, since I was between these two lights. 

I went with a JetBeam, which I should be getting any day now, and might be sorry. :sigh:

I really like the style of the JetBeam, but the Fenix seems to out-perform it in every respect (though the Jet puts out more actual light, the Fenix will still "feel" brighter).


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## Tronic (Jul 9, 2007)

Thanks for this great comparison! :twothumbs


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## aceo07 (Jul 9, 2007)

Thanks for the detailed review.

I wish the runtimes were much better, especially for low.


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## nerdgineer (Jul 9, 2007)

Another excellent review, selfbuilt. You are making yourself the new biblical reference standard for flashlight reviews.....

BTW, you have once again confirmed my opinion that Fenix remains the current champion for battery efficiency in flashlight design.


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## jsr (Jul 9, 2007)

Wowzers that's an amazing review. Has so much great detailed info and objective test results. The only thing that would make it better is more pics...sorry, flashlight p*rn.

I almost pulled the trigger on a Jet-u...it looks soooo nice, but held off due to the previous MKII and MKIIx Jetbeam releases reporting so many issues. Glad I did. I do like the increased output, but the contact issues make it a no go for me. I like to use my lights and not have to worry how clean the threads are. All my lights work even with dirty threads...sure, they might not be optimally bright, but if I need light, or need to switch modes, I know it will work.


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## THE_dAY (Jul 9, 2007)

:thumbsup:just the reveiw i and many others were looking for!

thanks selfbuilt!


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## selfbuilt (Jul 9, 2007)

Thanks for all the positive comments everyone.

I too am a little disappointed with the Jet-u runtime on low. Just double-checked Chevrofreak's excellent curves for the L0D-CE, and it seems mine is star performer - my L0D-CE lasted almost an hour and half longer than his did on alkaline.

I'm going to try the Duracell 1000mAh NiMH on low on both lights, and will update the graphs above when it's done (likely sometime tomorrow).

As for flashlight p*rn, x2x3x2 has always has great detailed disassembly pics on his review site, and ernsanada always does excellent outdoor shots. I figure I can't compete there, so I thought I'd save my bandwidth for beamshots and graph.


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## ernsanada (Jul 9, 2007)

What distance did you shoot your beam shots?


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## selfbuilt (Jul 9, 2007)

ernsanada said:


> What distance did you shoot your beam shots?


I didn't measure exactly, but it was about half a meter (~0.5M). Roughly the same as the beamshots in my multi-level 1AA review.


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## regulator (Jul 9, 2007)

Nice review and great info Selfbuilt. Do you think you could do a runtime plot running low mode with a lithium ion cell. It is supposed to provide more light than medium mode using a NiMh but substantially longer runtime - 3.5 hours.

Thanks.


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## lumenal (Jul 9, 2007)

Excellent comparisons selfbuilt. Thanks for the time and effort. :twothumbs

I've been on the fence regarding these 2 lights - it seems the Fenix Lod Ce is the one for me.


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## selfbuilt (Jul 9, 2007)

regulator said:


> Nice review and great info Selfbuilt. Do you think you could do a runtime plot running low mode with a lithium ion cell. It is supposed to provide more light than medium mode using a NiMh but substantially longer runtime - 3.5 hours.


I'm currently doing NiMH run tests, but may try it tomorrow. I'm wary of low mode 10440 runs, because you have to watch it like a hawk to make sure you don't run down your batts. I may stop the runs at intervals to test voltage, to be on safe side. I'll keep you posted ...


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## GhostReaction (Jul 9, 2007)

Excellent comparison review. :twothumbs:

It makes my option clear on which light to choose.

Hope you would do more great reviews


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## Grumpy (Jul 10, 2007)

My two Jet-u lights do not remember the last setting unless I leave them turned off for 15 seconds before turning back on. Anyone else have this same issue?

As I understand it if I leave the light on more than one second and it blinks I should be able to turn it off and it should come back on at the previous level.

It does not unless I leave it off for several seconds before turning it back on.

I think that this is a defect. Anyone else have this same problem?


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## selfbuilt (Jul 10, 2007)

Just updated the low graph to include NiMH runtimes. The Jet-u clearly does better on NiMH than it did on alkaline. Interesting that my L0D-CE has exactly the same runtime to 50% on alkaline with NiMH, with only a slight bump in output (usually see more of a difference between battery types on most lights). The Fenix clearly seems to have a very well optimized circuit for running on low mode. 10440 low mode runs are currently underway.

FYI, I'm also working on a review of some of the popular single-stage 1AA cree/SSC lights from DX/Kai, as compared to earlier models I've moded to cree/SSC (e.g. Elly, Vippa, etc.). Should have at least the preliminary review up by the weekend, assuming the last of the lights arrive as expected.

Oh, and I'm about to update my multi-level 1AA cree/SSC light review with the new v1.2 C-LE runtimes: 
Rexlight, DX X.1 & X.V, Jetbeam MkIIX & CLE, Fenix L1DCE review: RUNTIMES + BEAMSHOTS

That review will continue to be updated as new lights come in (especially the LM-301 which has just shipped ).


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## f22shift (Jul 10, 2007)

anybody know the runtime of the l0d on strobe?


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## Kelvino (Jul 10, 2007)

:goodjob:


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## gunga (Jul 10, 2007)

You rock selfbuilt! THese reviews are so helpful!

I'm also extra proud your a Canadian!

No more of this CONUS stuff...


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## selfbuilt (Jul 10, 2007)

Thanks for all kudos - it's nice to know the results are appreciated! 

Just added the Lo mode runtime on 10440, and the Jet-u finally pulled ahead of the L0D-CE. Nearly 2.5 hours to drop-off on the Jet-u vs 2 hours on the LOD-CE, for exactly the same output.

Too bad about the Jet-u Hi mode results on 10440, but honestly I'm rethinking the whole idea of these batteries in these lights. Doesn't seem like a safe idea to run on Hi in the L0D-CE either, since we seem to talking about ~3C discharge rate here.

Be safe everyone! :twothumbs



f22shift said:


> anybody know the runtime of the l0d on strobe?


No one has done this to my knowledge, but I remember Chevrofreak had looked at it on the P1D-CE when it came out. As you'll see here, strobe runtime wasn't even as good as Medium (Primary) mode:
https://www.candlepowerforums.com/threads/144407

I expect it's likely similar for the L0D-CE, but haven't tried it.


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## aceo07 (Jul 10, 2007)

Wow. I'm surprised the Jet-u has a longer low runtime on 10440 than the L0D-CE.


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## gunga (Jul 11, 2007)

Okay, I just got my Jet-u, and own the LF2 (cree) and used to own an LOD CE. THe LOD CE is gone so I'm going on memory only.

A few observations on the jet-u:

- Wow, that's a really wide, smooth flood. It has no throw tho and feels a bit weak due to the flood but is good for close range stuff.
- It's small and beautiful. Wish other lights could be this nice.
- The bottom is a bit narrow for tailstanding, but it does work.
- It needs a post it note on most cells to reduce battery rattle.
- It came with insanely dirty threads, but after a good clean and lube, is super smooth.
- The memory feature is pretty good. It is a benefit if you like to start on low etc. It can be a bit flakey at times, but is generally good.
- I can notice the PWM at times, but it's not bad.
- Performance on 10440 is a bit scary. Turns blue on high and heats up after 30 secs. Gets quite hot on medium too. It IS brighter of course.

I think I will try to EDC this light (using ni-mh). It's small and beautiful, feels great in the hand, and the close to low-medium range performance is quite good due to the flood.

A few notes about the competition:

- THe Fenix is a definite pocket canon. Great light and good for many CPFers. Too bad it has no low mode on 10440 and the finish is slippery and a bit thin.
- The Liteflux LF2 is great on 10440, giving a nice wall of light (at 50%) a low low, and over discharge protection. It's not a canon like the Fenix, but might be my favorite AAA light. It's also good with ni-mh but the overdischarge protection works much better with 10440s.

Hmmm, I will have to play around to see which light to EDC...

:thinking:


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## selfbuilt (Jul 11, 2007)

gunga said:


> I think I will try to EDC this light (using ni-mh). It's small and beautiful, feels great in the hand, and the close to low-medium range performance is quite good due to the flood .. THe Fenix is a definite pocket canon. Great light and good for many CPFers. Too bad it has no low mode on 10440 and the finish is slippery and a bit thin.


Good summary of the Jet-u's physical attributes, I think you captured that well. :thumbsup:

I too like the size and beam characteristics. BTW, the Jet-u also lacks a truly low mode on 10440 (like the L0D-CE, it has exactly the same output on lo). Of course, I compensate for this by carring a Photon Freedom on my keychain as well (as a "backup" ).

To give it a fair shake, I'm now EDCing the Jet-u for a bit (on regular batteries) to see how I like it in real world use. If it can consistently remember to come on in low mode, I may just keep EDCing it ...


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## liquidsix (Jul 12, 2007)

Glad I read this review. This helps me justify sending my jet-u back, and getting a fenix L0D. Looking at the area under the graph for your runtime plots, it seems the L0P is more efficient overall. <br/>Then again, I've heard there isn't a 1 to 1 correlation between output and battery consumption so maybe I'm wrong. If the Jet-u's output was the same as L0D on all levels, then maybe it would prove to be just as efficient.


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## selfbuilt (Jul 12, 2007)

liquidsix said:


> Looking at the area under the graph for your runtime plots, it seems the L0P is more efficient overall. <br/>Then again, I've heard there isn't a 1 to 1 correlation between output and battery consumption so maybe I'm wrong. If the Jet-u's output was the same as L0D on all levels, then maybe it would prove to be just as efficient.


Good observations ... but it's hard to say, since the Jet-u has higher output on almost all levels, and with very different beam characteristics. 

I don't think it's entirely fair to take area under the curve measures, since my milk carton lightbox is not a true integrating sphere by any stretch of the imagination. Judging from Chevrofreak's and Quickbeam's numbers on lights we have in common, I'd say my home-made lightbox typically underestimates true outut differences (i.e. the Jet-u could be even brighter than it seems on these tests). However, I suspect floody lights are more accurately sampled by my method than throwers are, so it could be a wash in this case.

And note in the one test where output was the same (10440 on low), the Jet-u outlasted the L0D. Of course, on Hi on NiMH the Jet-u underperformed for both brightness and runtime, so it may be Jet-u does better on certain modes/battery types ...


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## aceo07 (Jul 13, 2007)

I really like how the Jet-u is smaller, but the L0D-CE runtimes are much better.

I think if they can get the primary and low runtimes up more, it's be a great seller. Only 1 hour for primary ouput on alk batteries isn't much. Also if the low ouput was actually much lower, maybe 1/3 as much and have at least 6hours on alk battery. Also improve the heatsinking.

I use my lights for hiking or camping, so I like to have longer runtimes.


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## datiLED (Jul 16, 2007)

I have been following these performance AAA light threads with great interest. After much research, comparison of reviews and a price/performance analysis, I have decided to go with the Liteflux LF2. The deciding factor was the ability to run on 10440 cells and the non detectable PWM on lower levels.

The JET-u is a looker, but lacks the performance of it competitors. The blueing of the Seoul after 15 seconds on a 10440 cell, is scary. I have the feeling that we will see these turning up in the B/S/T Forums soon. However, if the price drops into the 35+ range, I may consider buying one. I doubt that I would buy one used for fear of an overheated LED.


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## Shaocaholica (Jul 18, 2007)

Can the head be opened at all to perhaps put some better heatsinking on the LED for Hi+LiON mode?


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## mchlwise (Jul 25, 2007)

I found a great use for my Jet-u last night. 

It was a nice night and we were having a late-night snack out on the patio. We have a typical patio table with a typical fabric patio-table umbrella over it. I wanted to shed a little light on the table without turning on the house backyard lights which would attract lots of bugs and ruin the whole ambience of the tiki torch, etc. 

So I clipped my Fenix L1Dce onto the umbrella shining down on the table. It projected some nice light, but it was only useable on about half of the table. 

Then, I remembered my Jet-u. 

I trew a NIMH in it and hung it in the same spot as the L1Dce. 

The Jet-u projected a nice pleasing even light over the entire table and beyond. Since there was no hot-spot to speak of, it wasn't distracting or overly-bright for somewhat night-adapted eyes. It was just a very nice useful light that was perfect for that application. 

:twothumbs

Again, this light's not a thrower, but if you need close-range even light, it's GREAT.


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## JETBeam (Jul 25, 2007)

Shaocaholica said:


> Can the head be opened at all to perhaps put some better heatsinking on the LED for Hi+LiON mode?


Hi shaocaholica,

FYI, afraid that the head can not be opened!

Best Regards,


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## selfbuilt (Aug 10, 2007)

After EDCing the Jet-u for the last several weeks, I've decided to keep it on my keychain. Despite the lower efficiency on regular batteries, and inability to run 10440 on Hi, I'm grown accustomed to its 3 main advantages over the L0DCE:


Very floody beam
High freq PWM not noticeable in everyday use (L0DCE was very noticeable)
Memory feature allows me to have turn it on on Low everytime

Of course, I've also taken to carrying a AA/14500 thrower on me as well (currently testing out the Rex 2.1 - very nice). If you only had one light on you, you might want to stick with the throwy L0DCE as a good all-purpose light.

Whatever you choose, enjoy the light!:candle:


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## swxb12 (Aug 10, 2007)

You forgot to mention that the Jetbeam looks and feels nicer, too . Think I'm going to become an AAA form-factor light collector.


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## ns66 (Aug 23, 2007)

thx for the great review

i just wish the light has lower low and last longer, we got 2 other modes for brightness, this low mode got to be for book reading and survival, so low low power and long long runtime should be much better


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## Long RunTime (Jan 4, 2009)

nerdgineer said:


> Another excellent review, selfbuilt. You are making yourself the new biblical reference standard for flashlight reviews.....
> 
> BTW, you have once again confirmed my opinion that Fenix remains the current champion for battery efficiency in flashlight design.


:thumbsup:+1


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