R.O.P. Roar of the Pelican mini-FAQ II

[ElectronGuru]

We've learned enough about AWs latest battery (IMR26500) to add it to the master thread.

The bad news
The IMR26500 (aka IMR/C) puts out near charger levels of voltage for some time and is therefore prone to poofing the Pelican 3854-H bulb.

The good news
While the 6.0v 3854-H does blow, the 7.2v 3853-H not only works with these cells, it works very well with zero rest time (thanks to member: lctorana). And Lux should be adding the 3853's to the destructive test group this month!

Result
Once the cells fit, you have a compact, high performance, easy to use, low cost ROP platform:

Mag 2C - $20
batteries - $30
reflector - $10
borofloat - $6
3853 set - $8
total - $74​

 

[KevinL]

We've learned enough about AWs latest battery (IMR26500) to add it to the master thread.

The bad news
The IMR26500 (aka IMR/C) puts out near charger levels of voltage for some time and is therefore prone to poofing the Pelican 3854-H bulb.

The good news
While the 6.0v 3854-H does blow, the 7.2v 3853-H not only works with these cells, it works very well with zero rest time (thanks to member: lctorana). And Lux should be adding the 3853's to the destructive test group this month!

Result
Once the cells fit, you have a compact, high performance, easy to use, low cost ROP platform:

Mag 2C - $20
batteries - $30
reflector - $10
borofloat - $6
3853 set - $8
total - $74​

Nice findings

I considered the IMR's, but I also remember my Sub-C (30A rated) pack hot off the charger poofed plenty of bulbs, which really annoyed me. The pack was heckofabright though.

The difference with NiMH is that resting overnight will drop the voltage to safe levels, whereas with IMR you're gonna be waiting a long time for the self discharge to kick in.

As always, still amazes me that this light is going strong.

Where are you folks buying the 6AA-to-2D adapters from these days?

 

[45/70]

Nice findings

I considered the IMR's, but I also remember my Sub-C (30A rated) pack hot off the charger poofed plenty of bulbs, which really annoyed me. The pack was heckofabright though.

The difference with NiMH is that resting overnight will drop the voltage to safe levels, whereas with IMR you're gonna be waiting a long time for the self discharge to kick in.

As always, still amazes me that this light is going strong.

Where are you folks buying the 6AA-to-2D adapters from these days?

Hey, Kevin :wave:

I'm not much help with where to find 6AA-2D adaptors, I'm still using one of modamag's originals.

What I'd like to do is get away from the 6AA-2D setup altogether, and maintain the 2D size. Ya, I know that's the original setup and all, but even the hobby cells I use (CBP 1650, Elite 1700 etc.) just don't last very long (in regards to number of cycles, not runtime). I can't imagine that Sanyo 2700's et al, last as long, and of course, are poor performers from the get go anyway.

If we could get LiFePO4 D cells (3.2 Volt) and run the 3854, that'd be an acceptable combo, I would think. Another possibility is 3.6-3.7 Volt Li-Ions in D size with the 3853. Unfortunately, neither of these at present, are available. For now I guess, I'll stick with Elites.

I'll always want my ROP to be a 2D. It looks like your average M@g, smells like your average M@g, tastes like your average M@g thinking, but when the uninformed pick it up, point it at their face and turn it on...........:naughty:

Dave

 

[Mjolnir]

There are some D cells at Kaidomain, both protected and unprotected. They are $22 and $16 respectively, so there is chance that they could be of decent quality.

 

[Alan B]

I have been using the unprotected KD D cells (for some other projects). They have been tested here on CPF at about 4.8AH and can handle about 10 amps. No problems with protection circuits limiting current, etc. However no safety either.

 

[KiwiMark]

There are some D cells at Kaidomain, both protected and unprotected. They are $22 and $16 respectively, so there is chance that they could be of decent quality.

I have both and find that the unprotected D cells work well.

Protected D cells work thusly:
3853-L - :thumbsup:
3854-L - :thumbsup:
3853-H - Probably will work, don't do any resistance fixes and cross fingers.
3854-H - Too many amps, the protection circuit will trip every time.

It seems that around 3.5 - 4.0 A is the limit for the protection circuit and the 3854-H will pull around 4.4A so it just doesn't work with the protected cells.

My protected cells and my 3854-L bulb are my favourite combo - around 2 hours of run time, nice light (colour, brightness, etc) and the bulb is quite tolerant of the voltage it is getting so no . This is great for every day use as a bright incan 2D that makes a standard 6D look pathetic.

My unprotected cells and 3854-H is nice and bright but would be pushing it to get 1 hour and it isn't a good idea to push the limits with unprotected cells anyway. OK for occasional use though.

The 3853-L only draws 1.6A while the 3854-L draws 2.0A, but Lux says that the 3853-L has not survived well in his tests:
http://i61.photobucket.com/albums/h75/pike444/bulbs/3853-L.jpg
http://i61.photobucket.com/albums/h75/pike444/bulbs/3854-LROP.jpg
I haven't blown a 3853-L yet and it is a nice light in use, but he 3854-L should last much better since it is capable of withstanding the full 8.4V (with a massive 1.2V margin) from 2 fresh Li-ion cells (IMR, D cells or whatever).

The 3853-H & 3854-H are the opposite way around to the L bulbs with the 3853-H tolerating much more voltage and therefore making it a good option for a brighter Li-ion ROP. Drawing around 3.5A instead of 4.4A means it should work most* of the time from KD protected D-cells.




* It is a nuisance when the 3853-H wont turn on - I sometimes end up having to partly unscrew the tailcap to up the resistance a little. Once the bulb is warm I can turn the light on and off with no problems. I think the combo of 3853-H & KD protected D cells is not bad if it works each time, but may need some sort of resistance increasing measure on some torches. It works fine every time on one pair of protected D cells and sometimes gets fussy on another pair, so it is a bit hit and miss with this combo.

 

[Mjolnir]

From my preliminary use, it seems like the ROP low is way more practical. It is still very bright, even when compared with high output LEDs, but it has MUCH better color rendition (in fact, it makes all of my LED lights look alien by comparison). I really can't tell all that much of a difference between the low and high bulbs, at least with the cells I am using (I haven't done any resistance mods on the switch yet).

 

[KiwiMark]

From my preliminary use, it seems like the ROP low is way more practical. It is still very bright, even when compared with high output LEDs, but it has MUCH better color rendition (in fact, it makes all of my LED lights look alien by comparison). I really can't tell all that much of a difference between the low and high bulbs, at least with the cells I am using (I haven't done any resistance mods on the switch yet).

The ROP low is easily twice as good if you like more run time. The ROP high should be noticeably brighter (not lots brighter, but should definitely be noticeable) in a side by side comparison, but the ROP low should be more than bright enough for . . . well just about anything really. ROP low = plenty of light from a 2A current draw.

 

[45/70]

Great information, gentleman! :thumbsup: Ideally, I'd like to stay with the 3854H/3854L combo.

I really can't tell all that much of a difference between the low and high bulbs, at least with the cells I am using (I haven't done any resistance mods on the switch yet).

Mjolnir, all I can say is, with the full switch fix and 6 good Elite 1700's, you don't need a light meter to tell the difference between the 3854H and the 3854L. I would say, to my eyes anyway, the H is at least half again as bright, probably closer to twice. It sounds like your batteries lack sufficient punch to drive the 3854H. What cells are you using?

It's kinda funny how I first discovered when my cells were "over the hill". I had been using CBP 1650's for a while (20-25 cycles maybe?) with the 3854H and I put in a 3854L for some reason or another, and it was brighter! They really don't last too long @4.3 Amps. And, as I mentioned before, if your using a 6AA-2D pack with regular high cap NiMH's, they just don't cut it in an ROP. They're fine for the low, but that's about it.

Dave

 

[Mjolnir]

I am actually using 18650s, since I already have a PILA IBC charger, and no decent Nimh charger. I really don't want to mess around with 6 cells and an adapter. I am fully aware that the cells are probably causing a reduction in brightness with the high output bulb, although they are probably as good as any 18650's around. I may get some lithium ion D cells eventually (which should stand up to the current better), but right now the low bulb is enough (and has much more runtime).

 

[KevinL]

Interesting. I am using 18650's as well, real high quality cells that have stood up to much over the years, but with no resistance fixes. The difference between L and H bulbs is very, very clear. It's even clearer on high-rate NiMH (6xSubC, 30A rated) in the 'original' 4D ROP that started it all. No resistance fixes on that one either.

L is a very practical bulb, but I like H...

Having popped more H than L, I now have a surplus of L bulbs. Oh, the L is also very resilient to instaflash, come to think of it. My high rate NiMH pack pops H for breakfast, but L stands up to the best I can dish out at it. I wonder how tolerant it would be of IMR cells.

As I consistently remind people, the ROP is particularly unforgiving on poor grade batteries. Regular NiMH don't cut it, you need high-rate NiMH. These days we prefer the Eneloop - good to five amps. We didn't have Eneloops when I started so we recommended CBP's.. now we have the best of all worlds

Also, amongst other observations, ROP LE's are dimmer than their NiMH cousins. Simple reason.....18650's have more sag than high-rate NiMH.

 

[KiwiMark]

Also, amongst other observations, ROP LE's are dimmer than their NiMH cousins. Simple reason.....18650's have more sag than high-rate NiMH.

Unless you use IMR 18650 cells. They work great with the ROP Low, but may the high bulb.

 

[ElectronGuru]

the L is also very resilient to instaflash, come to think of it.

The 3854-L is some kind of alien super bulb. Here's a photo study comparing it to the 3853-L. Blue is the 7.2v 3853L and red is the 6.0v 3854L.

 

[Mjolnir]

Has anyone else used the 8.3 mm opening MOP reflectors from KD? Mine gives my ROP a very large hotspot that is elliptical, not round (because of the filament). Most of the beamshots that I have seen of the ROP have smaller hotspots than mine. Given how large the reflector is, I did not expect such a large hotspot. In fact, my T10L outthrows the ROP low, while my 3D malkoff maglite probably outthrows the ROP high as well. Perhaps the bulb can't go far enough out into the reflector to focus properly, or maybe those reflectors simply aren't designed for throw at all. The elliptical beam pattern is quite annoying though...

Also, where can I find more info about IMR cells, and how they differ from normal Lithium ion cells in usage? IS it just as bad if they are overdischarged?

 

[45/70]

These days we prefer the Eneloop - good to five amps.

Ehhh, I duno about that one. I think eneloops are great. I've replaced just about all my AA and AAA NiMH's with them. The way I look at it though, a NiMH cell should hold at least 1.2 Volts under the load applied to it.

If you look at Tom's (SilverFox) graphs, @4 Amps, the eneloop is just about as bad as the Sanyo 2700 (the 3854H draws 4.3A in my ROP). Different in some ways, but overall, very similar. I'd say the eneloop is good for 2 Amps, maybe 3 in a pinch. Not ROP 3854H material.

If you look at the now discontinued CBP 1650's graph, you can see it holds over 1.2 Volts for about half it's discharge, @ 5 Amps. The eneloop falls to 1.15 Volts almost from the start, and it doesn't get any better from there. :sick2: The Sanyo 2700 holds a tiny bit better voltage at the start, but drops off as well. Actually the CBP 1650 doesn't drop to 1.15 Volts (basically where the eneloop and 2700 start) until it starts to drop off, period. If you look at the Elite 1700's graph (from CheapBatteryPacks), you can see it holds it's voltage a little better than the CBP 1650, but @ 10 Amps! Both the CBP 1650 and the Elite 1700, would of course, do better at only 4 Amps.

So, what does all this BS mean? Well, incans are driven by voltage, not current as LEDs are. So let's say we have a 6AA-2D pack that will run under a 4 Amp load (approx 3854H in an ROP) and average 1.2 Volts per cell through 80% of the discharge (CBP 1650/Elite 1700) and a 6AA-2D pack that under the same load only averages 1.13 Volts (eneloop/Sanyo 2700). Average pack voltages would be 1.2x6=7.2 Volts and 1.13x6=6.78 Volts respectively.

Now let's look at Lux's chart in the Destructive Incan Bulb Tests thread for the 3854H. At 7.2 Volts we get an estimated 1044 bulb lumens. At 6.8 Volts we get a predicted 876 bulb lumens. That's a difference of 168 lumens. Not that big of a deal really, but keep in mind the higher an incan is driven the whiter it is as well.

To me it makes a difference. On the other hand, if runtime is what you're after and the amount/quality of the output is secondary, go with eneloops or the high cap NiMHs. The hobby battery solution does sacrifice runtime, but it's brighter and whiter throughout the run.

I have to say, I'm getting like Mjolnir though, after almost 4 years with my ROP, I'm tired of fiddling with 6 batteries and the carrier, need to find a 2D Li-Ion solution. :sigh:

Dave

 

[45/70]

Also, where can I find more info about IMR cells, and how they differ from normal Lithium ion cells in usage? IS it just as bad if they are overdischarged?

Mjolnir, this probably isn't what you're looking for and you may have already checked it out, but ... Lithium 18650 Safe .......

Dave

EDITED, Screwy link

 

[KevinL]

Interesting - we always used to think the Eneloop was great at high amperage and the ultimate ROP bulb.

2C or 2D Li-ion should do fine.. or a straight stick of six SubC which is what I used to have

Is the ROP 4 years old already? That is old, as lights go. It has been a fantastic run.

Electronguru....what's up with the L? Surprisingly thick filament?

 

[ElectronGuru]

Electronguru....what's up with the L? Surprisingly thick filament?

Not sure as to the cause, but it seems to combine the best properties of efficiency and durability, including a very wide voltage range.

 

[TEMA]

Hi guys!

I'm new here and I've decided to buy a 6D Mag, and build a ROP from it. I have done some research on the forum, but I'm still confused with the reflectors. Since I haven't had any Mag in my hands, I dont't know what is the difference between cammed and camless reflector.
Now I use a Fenix P3D, it doesn't have throw, so I want a beam range between 70m defocused and min.300-400m focused. Which reflector would be appropriate for my needs? LOP or SMO?

Thanks

 

[ANDREAS FERRARI]

TEMA-we joined CPF at the same time but you only have 1 posting and I have over 500.Does that mean I have no life!:mecry:

As far as your question goes you can't get 300-400m of throw with a standard maglite head and a Pelican bulb.A ROP is mostly flood regardless of which reflector is used.My favorite ROP features a MOP reflector and a lightly frosted bulb(using Armour Etch).It produces a nice smooth beam that will light up a 100m field-but not much further.

The cam on these reflectors allow you to focus the bulb but can be unscrewed if necessary.