# ROP 2C Mag 3853 vs. 3854 100yrd shootout *NEW**Pictures***



## bigchelis (Oct 28, 2009)

Hi all,
Thanks to all of you here I was able to build and test my 2C Mag ROP. 





Ingredients:

2C Mag = contact: Mirage_Man = he makes them accept IMR C cells.
*Note: If you have an old 2C Mag with serial # beggining with a number as opposed to a letter it will fit IMR C cells with no boring needed.*

UCL lens = lighthound.com
http://www.lighthound.com/521mm-UCL-Lens-for-Mag-C-amp-D-Size-Flashlights_p_44.html


IMR C cells = 2 of them purchased from lighthound.com
http://www.lighthound.com/AW-IMR-26500-2300mAh-LiMN-rechargeable-lithium-battery_p_3046.html


ROP 3854 vs. 3853 = They come in 2 in a pack and consist of a High and Low variant in each set.
http://www.batterystation.com/flashlight_lamps.htm


KD V3 Smooth Cammed Reflector $13 delivered.
*KD M*g SMO Reflector V3.1 15mm Opening SKU: S006165 *
http://www.kaidomain.com/ProductDeta...ProductId=5631

Then you have to put it together...Just plug and play with no modding needed.

Here we go now:
Here are the parts layed out.











Here are the ROP bulbs layed out:


----------



## bigchelis (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

I used IMR C cells for testing. I took pictures with my Olympus Stylus 850w digital camera on night setting. In real life I saw more light, but at least you can see how the output of each lamps compares to the next. I also used a tri-pod and a Fluke Multimeter. The Palm tree is 100yards away according to google earth.

Current Readings at the tail with topped off cells: My watt math is under no load.
3854L: 2.03A = ~ 16.69 watts
3853L: 1.52A = ~ 12.49 watts
3853H: 3.30A = ~ 27.12 watts

I didn't think the 3854H would work with the IMR C cells so I depleted them to 3.87v exactly/each.
3854H: 4.20A = ~ 32.5 watts

I was pleasantly surprised that the 3854H didn't instantly go poof on me so I then tried 2 topped off cells. Each IMR C cell was 4.11v.
3854H: 4.30A = ~ 35.33 watts

Note: I actually got 4.90A at the tail for a split second reading, but it settled and stayed put at 4.3A.

There was a moth, that kept buzzing in the beam which made that impression you see in the pic. 
Here is the 3854L (left) vs. 3853L (right)









Here is 3853H (Left) vs. 3854H (right) topped off IMR C cells











Here is the 3854H (Left) 3.87V cells vs. 3854H (right)


----------



## Hack On Wheels (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

The night setting doesn't keep settings locked between shots, does it? If the camera compensates for the lighting changes between shots, then unfortunately they won't do a very good job of showing the difference in output.

I'm glad to hear you are having good luck with the 3854H and the IMR cells though, I'm looking at doing that setup myself soon!

Have you got a preference for one of the bulbs yet?


----------



## bigchelis (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



Hack On Wheels said:


> The night setting doesn't keep settings locked between shots, does it? If the camera compensates for the lighting changes between shots, then unfortunately they won't do a very good job of showing the difference in output.
> 
> I'm glad to hear you are having good luck with the 3854H and the IMR cells though, I'm looking at doing that setup myself soon!
> 
> Have you got a preference for one of the bulbs yet?


 

As I suspected the 3854L has the same lazer type beam the 3853L has, but with more power. This is my favorate so far.

The camera setting is likely not the best, but I hope to get MrGman to do a video shoot-out later on. I also have my fingers crossed he will have another calibrated IS Sphere in his garage of thruth. I think if I could give you folks the real OTF lumens it would further help this review.

In terms of which was brightest to my eyes:
3854H = super bright and floody
3853H = similar to 3854H, but It did seem a tad less bright in the spill

3853L = lazer like beam pattern
3854L = lazer like beam pattern and noticeably more intense light at 100 yards. I like this one the best.


----------



## bigchelis (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

The Mag Tail cap if left stock makes it super tough to screw on. 
I took the paint from inside the tail cap as much as possible with a dremel cylinder type bit. Then I got the stock 2C spring and forced it as low as possible.


----------



## Hack On Wheels (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

Awesome, so the 3854L would be a great bulb to leave in the light for general use... but then if you want to really light up an area you can switch to the 3854H. That sound about right? I'm liking the sounds of this!

Lumen ratings would be pretty awesome to know, hopefully that happens. 

Interesting note about the tailcap... how much longer are the two IMRs than a couple of alkaline C cells? Did you consider just cutting down the spring or would that not have done as good of a job?



bigchelis said:


> As I suspected the 3854L has the same lazer type beam the 3853L has, but with more power. This is my favorate so far.
> 
> The camera setting is likely not the best, but I hope to get MrGman to do a video shoot-out later on. I also have my fingers crossed he will have another calibrated IS Sphere in his garage of thruth. I think if I could give you folks the real OTF lumens it would further help this review.
> 
> ...


----------



## Jay T (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

It does look like the camera's built in metering is adjusting the exposure settings on each shot. To see the power of the camera's auto metering take a look at this thread. https://www.candlepowerforums.com/threads/240241

If your camera does not have a full manual setting there is one work around you can try to "Lock" a constant exposure for all of the shots. 

Aim your biggest light down range. Give the shutter a half press. Half press is when the camera locks focus and exposure settings. Now hold the half press, turn off the big light and turn on the light you want to use. Still holding the half press? Take the shot. If you do this for each shot all of the shots should be made with the same exposure settings. (For best results you should be a three armed mutant or have a friend)


----------



## bigchelis (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



Jay T said:


> It does look like the camera's built in metering is adjusting the exposure settings on each shot. To see the power of the camera's auto metering take a look at this thread. https://www.candlepowerforums.com/threads/240241
> 
> If your camera does not have a full manual setting there is one work around you can try to "Lock" a constant exposure for all of the shots.
> 
> Aim your biggest light down range. Give the shutter a half press. Half press is when the camera locks focus and exposure settings. Now hold the half press, turn off the big light and turn on the light you want to use. Still holding the half press? Take the shot. If you do this for each shot all of the shots should be made with the same exposure settings. (For best results you should be a three armed mutant or have a friend)


 
Wow this is very good info...

I will re-take the pictures this Thursday. Tonight I have a hockey game to go to:twothumbs


----------



## Mjolnir (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

Once you figure out the camera settings, do you think that you could do a shot of the beams at about 30-40 feet away? I am currently using a different KD reflector in my ROP that I suspect has a less than ideally focused beam, so I am considering getting the reflector that you currently have for more throw. 

In my ROP I am using the batteryspace 4000 Mah IMR 26650 cells. They probably don't fit in a 2C maglite, but they do have more capacity than the AW cells and cost $3 less per cell. 
Do you have any idea of what the additional diameter of you C maglite was before boring? My cells seem to be about 26.35 mm; any idea if they would fit unbored?


----------



## bigchelis (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



Mjolnir said:


> Once you figure out the camera settings, do you think that you could do a shot of the beams at about 30-40 feet away? I am currently using a different KD reflector in my ROP that I suspect has a less than ideally focused beam, so I am considering getting the reflector that you currently have for more throw.
> 
> In my ROP I am using the batteryspace 4000 Mah IMR 26650 cells. They probably don't fit in a 2C maglite, but they do have more capacity than the AW cells and cost $3 less per cell.
> Do you have any idea of what the additional diameter of you C maglite was before boring? My cells seem to be about 26.35 mm; any idea if they would fit unbored?


 
In my backyard the fence is exactly 50 feet away, so I will figure this camera exposure thing and do beamshoots at 50feet and maybe to show the beam at 10feet in the house against a white wall.

The 4000mAh IMR 26650 cells will fit perfect inside a 2D Mag. They are the lenght of a single 18650 cell.

My Mag hosts was an older numerical serial number and didn't need boring, but my newer 2C which has C***as first number had to get bored to fit the IMR C cells. 

No, they would definitely not fit the newer C Mag at all. The IMR 26650 cells should be very usefull in a 2D Mag with a home made holder:twothumbs


----------



## Mjolnir (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

Well I actually already have the 26650 cells in a 2D maglite. I took a 1 inch inner diameter PVC tube (which fit perfectly inside the maglite body) and "bored it" out to fit the extra few millimeters from the 26650's. Of course, I don't have a lathe, so I have to use a drill press and a drill bit that was 1 inch, and then file it down a bit. The inside is fairly rough and there are some edges in it, but the cells fit well with no rattle at all when the tailcap is on.


----------



## Dioni (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

Very usefull beamshots, thanks bigchelis! :thumbsup:


----------



## ElectronGuru (Oct 28, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



Hack On Wheels said:


> how much longer are the two IMRs than a couple of alkaline C cells?



There's a comparison here:

https://www.candlepowerforums.com/threads/230003


----------



## ANDREAS FERRARI (Oct 29, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



bigchelis said:


> As I suspected the 3854L has the same lazer type beam the 3853L has, but with more power.
> 
> 3853L = lazer like beam pattern
> 3854L = lazer like beam pattern and noticeably more intense light at 100 yards. I like this one the best.



Thanks for testing these bulbs bigchelis.

So the 3854L is brighter than the 3853L at the same voltage.Just like LuxLuther's testing predicted.


----------



## KiwiMark (Oct 29, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



Hack On Wheels said:


> Awesome, so the 3854L would be a great bulb to leave in the light for general use... but then if you want to really light up an area you can switch to the 3854H. That sound about right? I'm liking the sounds of this!



That is exactly my experience. 



ANDREAS FERRARI said:


> So the 3854L is brighter than the 3853L at the same voltage.Just like LuxLuther's testing predicted.



The 3853L also goes yellow a bit quicker as the cells run down, the 3854L has a better colour for longer.



bigchelis said:


> In terms of which was brightest to my eyes:
> 3854H = super bright and floody
> 3853H = similar to 3854H, but It did seem a tad less bright in the spill



I have also noticed that the 3853H isn't as bright, but it is likely to last much better as it can tolerate quite a lot more voltage before . The 3853H certainly isn't a bad bulb, just not quite the same intensity as the 3854H.


----------



## ANDREAS FERRARI (Oct 29, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

+1 to every statement by KiwiMark!!!!!!!


----------



## bigchelis (Oct 30, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

I manage to put the camera on auto mode and what you see now is the same exposure for all shoots taken. I took moved the tri-pod 15 feet from the beige wall and I zoomed in to get the shape of the beam only. The smooth reflector doesn't make the ROP bulbs good for wall hunting, but outdoors they come to life.

The hotspots for all 4 lamps are nearly the identical size, yet the LOW variants provide a lazer like beam. The High bulbs actually have a nicer hot spots than the Low bulbs. 

The 3854H (left) vs. 3853H (right)








The 3854L (left) vs. 3853L (right)


----------



## Outdoors Fanatic (Oct 30, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

Great thread! But you really need to find a darker place... LOL

Thanks for sharing!


----------



## bigchelis (Oct 30, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****

I had the exposured fixed for all shoots 1/4 F3.5 and although the lights look brighter in person at least you can see how they compare to each other at 50 feet (Google Earth). I also used topped off cells for both High bulbs

You can really see how much better the 3854L is than the 3853L. I have put topped off IMR C cells in the 3854H bulb 6 times trying to get it to go , but it hasn't happened. 

The 3854H (left) vs. 3853H (right)









The 3854L (left) vs. 3853L (right)









Nailbender 2C MC-E 610 OTF (left) vs. P91 2 IMR 16340 450ish OTF(right)


----------



## KiwiMark (Oct 30, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



bigchelis said:


> you can see how they compare to each other



Yes you can, very well in fact. Nicely done :thumbsup:


----------



## bigchelis (Oct 30, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



KiwiMark said:


> Yes you can, very well in fact. Nicely done :thumbsup:


 

Thanks,

I put the last 2 pictures to have a referrence point of lights that MrGman has tested for real OTF lumens.


----------



## Kestrel (Oct 30, 2009)

I've only played with the 3853's so far, but recently I've read a number of times how good the 3854-L is. Thanks for the beamshots on that one. :thumbsup:


----------



## ^^Nova^^ (Oct 31, 2009)

I have always felt that the 3854L was similar to the higher end D26 bulbs (EO-9/P91 etc, not quite 1794 though...). Nice to see a comparison of them.

Cheers,
Nova


----------



## Mjolnir (Oct 31, 2009)

*Re: ROP 2C Mag 3853 vs. 3854 100yrd shootout ***Pictures****



bigchelis said:


> The camera setting is likely not the best, but I hope to get MrGman to do a video shoot-out later on. I also have my fingers crossed he will have another calibrated IS Sphere in his garage of thruth. I think if I could give you folks the real OTF lumens it would further help this review.



I think we would all appreciate true lumens reading, so we could finally compare the output of the ROP quantitatively to other lights. I would be interested in some bulb lumen figures as well.


----------



## tx101 (Oct 31, 2009)

Bigchelis, I hope you dont mind that I resized and joined your photos
together to make comparing them easier, saves from scrolling up and 
down the screen


----------



## PlayboyJoeShmoe (Oct 31, 2009)

You can get a pretty decent wall hunting beam if you take time to center up the bulb in the reflector.

To SOME degree the more powerful the bulb the less artifacts and such.

But I was doing 4C in 3D lights well before joining CPF and learned to tweak the PR base to get better beams.

Try it, I think you'll like it!


----------



## ZardHex (Nov 1, 2009)

Thanks for posting this! I was researching not too long ago about upgrading my ROP, but today i found this thread and was a little bummed reading your observations on the tightness of the beam for the lo compared to the hi bulbs...i definitely dont want to upgrade to a hi setup if i'm not going to keep that laser beam that i like so much (and, to my eyes, the hi bulbs don't seem to have any more throw than the lo's when looking at your beamshots) 

Great job on a handy post :twothumbs


----------



## PlayboyJoeShmoe (Nov 1, 2009)

Keep in mind his camera settings may not have been locked making everything look similar.

I have both high and low bulbs but don't have a low in a light right now.

Gotta hit the sack pretty soon but I'll try to get back to you with my observations.


----------



## bigchelis (Nov 1, 2009)

When you aim the ROP High and low bulbs at the pitch black sky they produce a beam. The ROP L's are at least 50% thinner than the floody ROP High bulbs. 

The ROP L bulbs have a tight beam and remind me a lot of the Tiablo A10 beam.:thumbsup:

3854L rocks:twothumbs:twothumbs:twothumbs:twothumbs


I may be getting a 2.5in Throwmaster to take some beamshoots with the camera settings on the same exposure for all shoots soon.

bigC


----------



## KiwiMark (Nov 1, 2009)

Both my 2D 3854 ROPs have good throw, but they ARE using fivemega's 2" deep reflector V2. My 3853-H is more floody - using a KD MOP reflector. My 3853-L is no more - I needed a host for my spare AW soft start switch.

Almost forgot - my 6D 3854 high is quite floody - KD MOP reflector in that one too.

But the high bulbs still throw pretty good - with that much light coming out you will get a reasonable range even from a floody beam.


----------



## Mjolnir (Nov 1, 2009)

From what I have experienced, the hotspot size is as follows, from smallest to largest:
3854L, 3853L, 3854H, 3853H. 
This also seems to be the order of filament size, since higher voltage bulbs tend to have larger/longer filaments. 
Although the L bulbs throw more for the output, the high bulbs definitely don't have less throw, they just have a larger hotspot, which is more useful. Of course, you get shorter battery life.


----------



## PlayboyJoeShmoe (Nov 2, 2009)

My ROP HI driven by 6AA has an approx 8" spot on the wall at approx 7'.

(change to low bulb)

The bright center (although it is a more diverse beam) is about 4" so yes it is more of a thrower.

Mine are running in SMO Aluminum reflector with a big hole.

ROP HI doesn't have quite the tight spot but driven well it is enough light so you probably won't notice.


----------



## bigchelis (Nov 3, 2009)

I just put my ROP bulbs in the 2.5in Throwmaster bezel from Fivemega and it throws at least 30~40% more.

I was really digging the Low bulbs more because the tight beam seemed to offer more throw, but now I can't tell the beams apart. The 2.5in bezel makes the High and Low bulbs have identical pencil like beam with the 2.5in bezel on both of them. Needless to say that the 3854H with a pencil tight beam throws more now and it sure does. 

3854H and 2.5in fivemega bezel = lazer like beam and throw is beyond what I expected. :twothumbs

bigC


----------



## Mjolnir (Nov 4, 2009)

bigchelis said:


> I just put my ROP bulbs in the 2.5in Throwmaster bezel from Fivemega and it throws at least 30~40% more.
> 
> I was really digging the Low bulbs more because the tight beam seemed to offer more throw, but now I can't tell the beams apart. The 2.5in bezel makes the High and Low bulbs have identical pencil like beam with the 2.5in bezel on both of them. Needless to say that the 3854H with a pencil tight beam throws more now and it sure does.
> 
> ...




If you think that your 2.5 inch reflector makes the bulb into "laser" then you should see what I did... I put a 3853L bulb in a cheap (much lower output) halogen spotlight that I have with a deep 4" reflector, running off of 2 18650s. It seems to throw almost as well as my stanley HID. Of course, the beam is more focused and it probably has a tenth of the output. However, I do prefer the nice warm incan light from the 3853 to the Stanley's 8000K HID bulb.

I also tried the 3853H bulb with the IMR 26650 cells with the 4 inch reflector. It was raining very hard out, but the amount of light that it could project hundreds of feet away was simply amazing considering how low the total cost of the setup was. Of course, the reflector is plastic (albeit a fairly thick, strong plastic), so I wouldn't want to run it with the 3853H on IMR cells long term. Anyways, I need the IMR cells for my 2D ROP!


----------



## bigchelis (Nov 4, 2009)

Mjolnir said:


> If you think that your 2.5 inch reflector makes the bulb into "laser" then you should see what I did... I put a 3853L bulb in a cheap (much lower output) halogen spotlight that I have with a deep 4" reflector, running off of 2 18650s. It seems to throw almost as well as my stanley HID. Of course, the beam is more focused and it probably has a tenth of the output. However, I do prefer the nice warm incan light from the 3853 to the Stanley's 8000K HID bulb.
> 
> I also tried the 3853H bulb with the IMR 26650 cells with the 4 inch reflector. It was raining very hard out, but the amount of light that it could project hundreds of feet away was simply amazing considering how low the total cost of the setup was. Of course, the reflector is plastic (albeit a fairly thick, strong plastic), so I wouldn't want to run it with the 3853H on IMR cells long term. Anyways, I need the IMR cells for my 2D ROP!


 

I assume the Stanley HID is the version WallMart sells, but is typically sold out.:sigh:

Now what 4in reflector are you using?????????


thanks,
bigC


----------



## Mjolnir (Nov 4, 2009)

Yes, the Stanley is the one from Walmart (it is also available from amazon). 

The 4 inch reflector is in a cheap coleman 4D spotlight/lantern (it had a fluorescent tube as well, but I took it out after I put in the batteries with higher voltage that I had lying around. The reflector is moderately scratched and damaged, but it still throws pretty well. The light itself previously had a PR bulb in it with far less output than even an 3853L. For some reason, the ROP bulbs also focus better than the stock bulb as well. I would say that the hotspot is only a few feet wide at about 200 feet (very rough estimation).


----------



## Kestrel (Nov 4, 2009)

OK, from what I understand, absolute maximum output can be achieved with the 3854-H on 2xIMR'C', but that voltage (with minimal 'sag' from the IMR's) can be borderline for this bulb depending on the individual build.

However, comparing the 3854-H on 6xNiMH (Eneloops) to the 3853-H on 2xIMR'C's, I'm guessing that real-world outputs should be comparable, but what about runtimes?

I know I could calculate theoretical runtimes (goodness knows I've done it enough), but I also know that voltage sag can be considerable and also usable watt-hours from the cells will suffer (to varying extents - I know the IMR's will hold up very well under these currents). In this case, I'd have to look up SilverFox's cell data as well as Lux's bulb data and recursively calculate voltages, currents, voltage sags, and watt-hours, for the two different bulbs & the two different cell chemistries... 

Any thoughts?


----------



## bigchelis (Nov 4, 2009)

Kestrel said:


> OK, from what I understand, absolute maximum output can be achieved with the 3854-H on 2xIMR'C', but that voltage (with minimal 'sag' from the IMR's) can be borderline for this bulb depending on the individual build.
> 
> However, comparing the 3854-H on 6xNiMH (Eneloops) to the 3853-H on 2xIMR'C's, I'm guessing that real-world outputs should be comparable, but what about runtimes?
> 
> ...


 

Some time ago while MrGman was testing my Mag P7 builds he tested my AW C cells. He applied 3.5A of current to 2 IMR C cells and under load there was zero sag and the voltage of 8.2v was the same with/out load. We also didn't get any sag with the black AW C cells at 3.5A load.

The test was also done with the IMR 18650 by MrGman during, but the IMR 18650 did suffer significant voltage sag and it affected the OTF lumens by a good margin. In fact here it is:

IMR 18650 with P7 P60 Direct drive = 350ish out the front
3 NiMH C cells (no sag) same drop-in = 600ish out the front

Granted one was a 6P hosts and the other was the Fivemega 3C hosts, but we used the same bezel and drop-in. The only thing different was voltage sag. Those NiMH C cells had zero at 3A, but the 18650 was down to 3.9v under the same load:sick2:

After this test I only use IMR C cells for my builds; especially ROP and P7 Mag builds.

bigC


----------



## PlayboyJoeShmoe (Nov 5, 2009)

So what you are saying in essence is that what I think is a good and bright ROP HI on 6AA Hybrids is leaving almost 50% on the table?

WOW!! if true.

Just used my Craftsman DVM to amp check my ROP HI and saw about 3.90 when it stabilized. Is that reasonable?


----------



## ElectronGuru (Nov 5, 2009)

Keep in mind, part of the poof equation is the charger, specifically the voltage it stops at. A 3854H is much more likely to poof charged to 4.2x2 or 4.3 then 4.0 or even 4.1. These cell are also still to new to know if things change with age/use.

The 3853L gained popularity right after the introduction of the IMR26500 because of so many blown 3854L's. 

Edit, I credit *this post* with revealing the 3853


----------



## Mjolnir (Nov 5, 2009)

I think that you meant that the 3854*H* was getting blown by IMR cells, not the 3854*L.* The 3854L works fine with 2 IMR cells, even fully charged (and I use 26650s, which might sag less than 26500s - of course, the stated max continuous load of the IMR C cells is 20 amps, and the 26650s are advertised as 10, so they might not sag less). 
My 3854H has worked at about 4.1 volts per cell, and I have not blown a bulb yet.

3.9 amps is lower than what I have been getting with IMRs. According to my ammeter, the 3853H bulb draws about 3.3-3.4 amps and the 3854H draws about 4.4. The 4.4 amps is also at nearly 8 volts at the beginning, so it could theoretically be a fair amount brighter than an ROP with AA cells.


----------



## Jay T (Nov 5, 2009)

PlayboyJoeShmoe said:


> So what you are saying in essence is that what I think is a good and bright ROP HI on 6AA Hybrids is leaving almost 50% on the table?
> 
> WOW!! if true.
> 
> Just used my Craftsman DVM to amp check my ROP HI and saw about 3.90 when it stabilized. Is that reasonable?



I just ran a quick test between 2 IMR26500 in a 2C mag and 6 eneloops in a 2D mag. I used the same bulb, reflector and glass for both.

The 2C started life as an 18650 ROP and has been treated with progold, the 2D started life life with a LED drop in and was stock.

The IMRs were rested at 4.17 and gave a ceiling bounce of 82 lux with a tailcap current of 4.38A. (note: for this light 4.17 seems to be the max safe point. I have blown a bulb or two at 4.18+. Your Mag may differ)

The Eneloops were fresh charged in a FM holder and gave 57 lux with a draw of 4.0A.


----------



## Mjolnir (Nov 5, 2009)

Jay T said:


> I just ran a quick test between 2 IMR26500 in a 2C mag and 6 eneloops in a 2D mag. I used the same bulb, reflector and glass for both.
> 
> The 2C started life as an 18650 ROP and has been treated with progold, the 2D started life life with a LED drop in and was stock.
> 
> ...



Wow, that is quite a bit of difference. Now all we need is someone to get these in an integrating sphere...


----------



## lctorana (Nov 5, 2009)

Jay T said:


> I just ran a quick test between 2 IMR26500 in a 2C mag and 6 eneloops in a 2D mag. I used the same bulb, reflector and glass for both.
> 
> The 2C started life as an 18650 ROP and has been treated with progold, the 2D started life life with a LED drop in and was stock.
> 
> ...


Just some thoughts to ponder:

Let's assume any differences between switch/spring internal resistance between the hosts is negligible.

The 3854H must have been a whisker from it's flashpoint at the IMR voltage. I would humbly suggest that the 3854H, if direct driven and putting out that much lux, would have impractically short bulb life and be delicate in the extreme.

The Eneloops, given being freshly charged, would have delivered 7.5V-ish under that load.

The other factor to consider is that there are eleven battery connections versus three for the IMR setup, when you think about it. That means an extra eight spots that can each introduce a milliohm or two of resistance.

My 3854H-equipped RoP is a 4C with 6x 4/5 NiMH Sub-C cells, so seven battery connections. Somewhere in between your two for output.


----------



## Jay T (Nov 5, 2009)

lctorana said:


> Just some thoughts to ponder:
> 
> Let's assume any differences between switch/spring internal resistance between the hosts is negligible.
> 
> The 3854H must have been a whisker from it's flashpoint at the IMR voltage. I would humbly suggest that the 3854H, if direct driven and putting out that much lux, would have impractically short bulb life and be delicate in the extreme.



Delicate in the extreme, Well it's been topped off several times, turned on and off a many more and it's still goin. From what I have read over the years about re rating hotwires is that instaflash territory is reached when the rated life is under a few hours. After the initial fire up (the most dangerous part) the constant drive was 4.4 amps. Looking at Lux's charts 4.4 A of drive current isn't that close to it's max voltage.


----------



## lctorana (Nov 5, 2009)

Jay T said:


> Looking at Lux's charts 4.4 A of drive current isn't that close to it's max voltage.


True, of course. I didn't look at that. We're only talking about 7.3V at the bulb, even with the IMR's then, aren't we?

That means, if I can assume the IMRs are delivering about 8V under that load, then it follows you must have about 0.16 ohms in circuit to drop that 0.7V, *including the burden voltage of the ammeter*. That would be only about half-way to the flashpoint, but remember that without the meter in circuit, the bulb will be driven even harder.


----------



## Mjolnir (Nov 5, 2009)

That is a pretty big voltage drop. According to those charts, my 3853H is only running at 7 volts, meaning that it is technically under-driven... However, If I do resistance mods then I won't be able to use the 3854H bulb without a serious risk of blowing it.


----------



## Jay T (Nov 5, 2009)

lctorana said:


> True, of course. I didn't look at that. We're only talking about 7.3V at the bulb, even with the IMR's then, aren't we?
> 
> That means, if I can assume the IMRs are delivering about 8V under that load, then it follows you must have about 0.16 ohms in circuit to drop that 0.7V, *including the burden voltage of the ammeter*. That would be only about half-way to the flashpoint, but remember that without the meter in circuit, the bulb will be driven even harder.



Already ran a test on that. Doing a wall bounce test ( So the light is locked in position) with the tailcap gave a reading of 25 lux. While using the meter to measure the current the lightmeter read 26 lux. It looks like the tailcap has more resistance that the meter. My tailcap is just the stock spring, no wire bypass. 

If you go by current drawn and look at Lux's charts most hotwires don't seem to be as impressive as most people claim. Most of the time people use the resting voltage and look at the chart and say "I have a 1500 lumen light". That little bit of resistance can really kill these things.


----------



## lctorana (Nov 5, 2009)

<cracked record>
Please don't underestimate ammeter burden voltage, particularly and especially with modern DMMs. Values of 0.25V and 0.4V and even higher are quite common. This is why I advocate ye olde Avometer Model 7, as this ancient meter only has a burden voltage of 0.1V at FSD on DC current scales.​</cracked record>


----------



## PlayboyJoeShmoe (Nov 5, 2009)

I have a second ROP HI running in a 5D light with 6 C Nicad from a drill pack that fell and broke.

I just found among the 14 cells 6 with 9+ Flash amp.

I got 4.14 at the tail of that light.

So I am giving up some brightness in the 2D with 6AA.

Someday I'll be able to get some nice C LiIons....


----------

