Jetbeam Jet-III Pro ST Best Driver/Circuit?

Hi Folks,

although following the discussions around the "after" Jet-III PRO IBS models, I couldn't find anything definitive about the differences of the two available driver circuits of the Jet-III Pro ST. Right now both versions are available, but the LVC (0.7-4.2 input voltage) seems to become rare while the Broad Voltage Circiut seems to prevail.

So there are a couple of questions.

1. Are there definitely only those two circuits mentioned above? At BOG I saw a "18650 only" mode (which is no longer available now), and at http://kazwholesale.en.alibaba.com/...eam_JET_III_PRO_ST_LED_Flashlight_18650_.html they specify the input voltage between 3.6 and 4.2V. Does that mean a third version of the ST that would run neither on (adapted) AA nor on CR123A cells?

2. As to the two "low" and "broad voltage circuit": which one of these is more efficient? Which one will deliver the lowest output? Which one the longest runtime on Med/High?

3. What means "Buck and Boost Current regulated"? Are both the LVC and the BVC fully regulated, or does a 18650 run partly unregulated in either of the circuits? What does that mean for the lifespan of the rechargeables used?

4. Finally: which one of the Jet-III Pro ST is the better flashlight? Of course, if there are no runtime differences this questions reduces to the decision which battery types should be used. Including (adapted) AA cells with the LVC or including 2xCR123A/R with the BVC. But still I'm interested in your experiences.

thank you

EDIT: Is the 0.7-4.2V circuit of the ST the same used in the Jet-I Pro V3.0?

dubliftment said:

EDIT: Is the 0.7-4.2V circuit of the ST the same used in the Jet-I Pro V3.0?

Click to expand...

I wasn't monitoring the Jet-III line but the Jet-I should have a different circuit than the Jet-III. Before releasing the Jet-I, JetBeam was saying that they are developing a new, more efficient circuit for it.

Hi,

I also, would like to know some of the answers you seek.

I have been searching and searching and can not seem to find much info on the JET-III PRO ST BVC vs the 18650 only version.

I hope that the BVC circuit has similar or better regulation than the 18650 version.

I would especially like to see a runtime vs output graph of the BVC to compare to the graphs done on these reviews;

https://www.candlepowerforums.com/threads/208280
http://www.light-reviews.com/jetbeam_jet-iii_pro_st/

Sorry if this is hijacking your thread, but from your original post you would also be interested in this.

-arjag
:candle:

As a basis for comparison, my ST/BVC R2 measured at the tailcap on a 4.0V 18650 3ma on lowest and 900ma at full power.

:thinking:

Does anyone have any more answers?

all I can say is that the Jet III ST BVC-R2 I bought some 2 weeks ago at Flashaholics.uk, thinking getting a good quality and compact mono-18650 flashlight, is noticeably less bright with a 18650 than with 2*CR123...:sigh:

I should have done better to take the "only 18650" (but Q5...) version from BOG, at this time, which was 30% less expensive, in addition...

well...as a Frenchman, I should have know that one's must always beware of the perfidious Albion...:tinfoil:

I bought the 18650 only version because it should have better regulation when using an 18650, and that is all I plan on using.

Thanks for the responses, I also posed this question here;

http://www.cpfmarketplace.com/mp/showthread.php?p=2402157#post2402157

And the answer seems to be that the ST BVC is semi-regulated, like the JET-III M BVC :green:

I am still hoping someone with the right equipment can do a output vs time graph for the ST BVC.

arjag said:

And the answer seems to be that the ST BVC is semi-regulated, like the JET-III M BVC :green:

Click to expand...

I belive it's exactly the same circuit, just smaller body.

arjag said:

I am still hoping someone with the right equipment can do a output vs time graph for the ST BVC.

Click to expand...

It should be identical to the M BVC

@Kremer

Well, this answers all my questions on the topic, Thanks.

@dubliftment

From what I can tell, the answers to your questions are;

1, The st comes in two forms, the 18650only and BVC,

I think there is a lot of misleading specs on sites selling stuff.

2, I think the BVC will have a [substantially] longer runtime on high than the 18650only at the expense not of being fully regulated. ie dimms somewhat before end of battery life.

compare graphs
ST 18650only
http://www.light-reviews.com/jetbeam_jet-iii_pro_st/
Hermes H20 <equiv to> J-III M <equiv to>ST BVC
http://www.light-reviews.com/hermes_h20/

I dont know which delivers the lowest output, but both should go VERY LOW

3, In the terms of driving a LED, Buck regulated means to bring voltage down from battery voltage to the Vf (forward voltage) of the LED. Boost pumps the voltage up to the Vf of the led from battery voltage.

Excluding losses, current and votage have an inversly proportional relationship. In this context a buck&boost circuit will buck when the voltage is above Vf. When the battery voltage drops below Vf the boost part kicks in and has to pull much more current from the battery to acheive the same brightness. I think this is part of the reason semi regulated acheives much more battery life (other part is the circuit is more complex and harder to build and design), as semi seems to buck untill battery reaches Vf and then direct drive.

4, which is better, the ST 18650only or the ST BVC.... Well that is subjective and armed with the information here, up to you to decide.

I think the 18650only is better as it has [close to] full brightness right up untill the battery is flat. I am willing to carry a spare battery.

I must mention that i do not own either of these lights, but have done a fair bit of research on them.

I hope this makes sense and is helpful without too many errors.

:candle:

I chose the BVC because I have about 20 free 18650's harvested from laptop packs. The BVC, being buck then current limited direct drive is nice and friendly with an unprotected li-ion, since the LED stops conducting below Vf which is not too hard on a li-ion. The light surely and noticeably dims down toward the far end of the battery charge, giving you plenty of time to feed it more cells or wrap up what you are doing. It eventually becomes a nightlight then starts a slow strobe at that minimum before completely going out many hours later.

The 18650 only version to my knowledge will deeply discharge a li-ion, and relies on the battery protection to stop, which I don't think is a good strategy. I think it's great if you don't mind full power for a long time, then unexpected darkness.

jdb said:

all I can say is that the Jet III ST BVC-R2 I bought some 2 weeks ago at Flashaholics.uk, thinking getting a good quality and compact mono-18650 flashlight, is noticeably less bright with a 18650 than with 2*CR123...:sigh:

I should have done better to take the "only 18650" (but Q5...) version from BOG, at this time, which was 30% less expensive, in addition...

well...as a Frenchman, I should have know that one's must always beware of the perfidious Albion...:tinfoil:

Click to expand...

Bonjour

Would be interested to know more about your experience with the Jet III ST BVC-R2 as I am thinking of getting one as well. I am interested in knowing what run time you are getting out of a 18650 2 or 3 hours ??(please let me know the make and amperage of the BATTERIES you use), also I would like to know how hot this get on long runtime 1h or 2 hours.
Je vous remercie d'avance.

SKYRAIDER59

Don't know if this will help you or not, i bought the Jet III Pro ST (18650 only) version shortly after it was released and am very pleased with it. On MAX using a trustfire 2500 mAh protected 18650, it ran for about 1hr 48 minutes before the protection kicked in and the light went out.

I really like the beam shape and tint, it's a very nice cool white not at all blue-ish or greenish, just pure nice white. If you look at my avatar, its actually my Jet III in a blue plastic mug on the runtime test on MAX and undergoing a waterproofing test as well.

I have other lights that are BVC and i find that they are brighter on 2xRCR123s than on 18650 but am not too clear on the runtimes. I tried looking for some information on the Jet III BVC but couldnt seem to find anything that wasnt already posted.

Perhaps you might PM flavio? (and post the results here in the thread obviously)

hyperloop said:

Don't know if this will help you or not, i bought the Jet III Pro ST (18650 only) version shortly after it was released and am very pleased with it. On MAX using a trustfire 2500 mAh protected 18650, it ran for about 1hr 48 minutes before the protection kicked in and the light went out.

I really like the beam shape and tint, it's a very nice cool white not at all blue-ish or greenish, just pure nice white. If you look at my avatar, its actually my Jet III in a blue plastic mug on the runtime test on MAX and undergoing a waterproofing test as well.

I have other lights that are BVC and i find that they are brighter on 2xRCR123s than on 18650 but am not too clear on the runtimes. I tried looking for some information on the Jet III BVC but couldnt seem to find anything that wasnt already posted.

Perhaps you might PM flavio? (and post the results here in the thread obviously)

Click to expand...

Hi Hyperloop

Thanks very much for your additional info, well appreciated, as you mentioned, there is not a lot on the Jet III PRO BVC, can you confirm if yours is the R2 2 mode or the Q5 3 mode, also are we talking 1.48h on full power 225 lumens or an overall run time with on/off to let the flash light cool down? Does she get pretty hot on a continous run?
Sorry about all the questions, but I better find out before I part up with my hard earned cash.
Best:wave:
SKYRAIDER59