# Bringing new life into a old Mag 3D, with low & high **Beamshots**



## Kestrel (Oct 19, 2009)

Edit: A new update at post #15, using the Pelican 3753-H in a Mag 4D, with comparison beamshots. 

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*A beginners hotwire, including pictures.*


A friend of mine (who has a few nicer lights such as a SureFire G2L and a Pelican M6) had an old Mag 3D with half-dead (at least) cells sitting in a closet, so I offered to ‘improve’ it for him. My goal was to keep costs to a minimum while using bulbs at their rated voltage (no overdrive) – high reliability being a consideration.

The subject:







The bulbs:





Left: old Mag 3 cell Krypton bulb, 3.6v??, approximate amperage 0.8 A, = ~*3 watts*.
Center: The new ‘low’, a generic 4.8v Xenon, 0.375 A, = ~*1.8 watts*.
Right: The new ‘high’, a 4.8v Xenon Pelican 3753-H, ~1.8 A, = ~*8.5 watts*.

The cell configurations:








Left: 3 half-dead Duracell D's with expirations of March 2004 and 2005.
Right: 4 new alkaline C’s.
Total amp-hours (comparing new cells) goes from 3x12ah= 36 amp-hrs to 4x8ah= 32 amp-hrs in the new configuration (only estimations using (low-drain-rate) numbers from Wikipedia). Edit: I know this isn't the technically correct way to add up the total energy content of this cell stack (that would be in watt-hours), but voltages from alkaline cells under low & high loads can vary quite a bit, creating quite a few caveats with that calculation. I just wanted to illustrate that 4xC could at least be comparable to 3xD in total energy content.
As you can see, I have used a modified tailcap spring instead of the stock Mag ‘battery crusher’ spring, as the new cell configuration adds an additional 1.5 cm of length. Upon assembly, the spring becomes inverted into the tailcap. Diameter issues were handled with a simple roll of cardboard.







Beamshots: (distance for both lights and camera are 6 feet)

A ~240 lumen Malkoff M60 that I always use as a benchmark:






Before:





Information from Mag gives ~*75 lumens* (initial, from new cells, not these half-dead expired alkalines) for a runtime of approximately *6 hours* (runtime taken from Duracell OEM spec sheet, not Mag's rather more optimistic number of 9-10 hrs). Note the horrible beam artifacts, much of which is coming from the pointed bulb.

The new (generic) 'low' bulb, a very rough estimate of ~*50 lumens* (initial) for a runtime of approximately *18 hours*:






The new 'high' Pelican bulb, a very rough estimate of ~*250 lumens* (initial) for a runtime of approximately *1 hour*:
(Note the very nice beam shape resulting from the linear filament in the Pelican 3753-H.)






(All Mag beamshots were taken with the reflector set to the tightest focus.)

After this very simple upgrade (it doesn’t get any simpler than this), I’m hoping my friend will find his Mag a lot more useful now.


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## MorePower (Oct 19, 2009)

Kestrel said:


> Total amp-hours (comparing new cells) goes from 3x12ah= 36 amp-hrs to 4x8ah= 32 amp-hrs in the new configuration (only estimations using (low-drain-rate) numbers from Wikipedia).



One small problem with your math: Amp hours for cells in series are not additive.


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## Kestrel (Oct 19, 2009)

MorePower said:


> One small problem with your math: Amp hours for cells in series are not additive.


I just wrote it that way for the simplest possible comparison between the pre- and post-mod capacity, going from 3D to 4C.

I can write it for watt-hours if you'd like but that introduces another error as you probably know: It's difficult to use the total voltage for the cell stack for the watt-hour calculation, as the difference in voltage drops under load should be pretty considerable between the low-amp bulb and the high-amp bulb.

But if it makes folks any happier...
3 D cells: 1.2v x 3 cells x 12 ah = ~43.2 watt-hours
4 C cells: 1.2v x 4 cells x 8 ah = ~38.4 watt-hours

So that's an *11%* loss in total energy capacity (watt-hours) compared to the oversimplified amp-hours comparison ... 

...

which also, amazingly enough, demonstrated *11%* less energy capacity. :ironic:

However, I didn't want to put much effort into that calculation, as the *12 amp-hrs* & *8 amp-hrs* numbers from Wikipedia used in that calculation were derived from low-draw applications, and will be somewhat less for higher-draw applications such as this one. In the past I have researched CPF for typical amp-hour & watt-hour contents of C & D -sized alkaline cells (for various drain rates) and have come across a range of figures. Silverfox has some pretty good data for Duracell alkaline D cells (9.4 a-h @ 0.5 A, 5.3 a-h @ 1.0 A, 1.5 a-h @ 3.0 A) but nothing for C alkalines.

In addition, looking at SilverFox's data, the voltage from alkaline cells drops pretty substantially during their discharge curve, further complicating an attempt to make a wattage or runtime comparison.


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## MorePower (Oct 20, 2009)

Well, I certainly didn't mean to tick you off. I just thought that if you're writing a "beginners" guide, you may as well get the fundamentals correct.

Regarding cell capacities at various constant current or constant power draws, Duracell has some nice charts on their OEM/Technical site.

LR14 chart

LR20 chart

You could use the constant power graphs to develop more accurate runtime estimates if you'd like.


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## Kestrel (Oct 20, 2009)

Wow, those Duracell discharge graphs are great!
Thanks a bunch, I have other C alkaline builds and this will be really helpful. :thanks:
Edit: Using the Duracell OEM data, I have calculated more accurate runtimes for all configurations and updated Post #1.
Estimated runtime for the high-current bulb has been particularly hard-hit, alkaline cells have far less capacity when run extremely hard.


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## Flashanator (Oct 20, 2009)

Great Stuff Krestrel.  Huge improvement over that Before pic. good stuff.


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## MorePower (Oct 20, 2009)

Kestrel said:


> Wow, those Duracell discharge graphs are great!
> Thanks a bunch, I have other C alkaline builds and this will be really helpful. :thanks:



Glad to be of help. The charts are a bit out of date, but should still be fairly accurate. I've used them myself when I didn't have time to generate my own data for estimates.


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## ElectronGuru (Oct 21, 2009)

Look'n good K.

If they're handy, I would consider also trying the 6.0v high and low bulbs. The 3854-L, for example, seems to do well in every configuration its thrown at. Another pre ROP favorite is a GH24.


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## mvyrmnd (Oct 27, 2009)

Love it!

I don't suppose anyone knows how I could get a few of those 3753's to Australia? Google has not been my friend.. :mecry:


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## Kestrel (Oct 27, 2009)

I plan on ordering a bunch of assorted Pelican bulbs in a few days, I can add a few packs of '3754' (containing a 3753-H and a 3704-L ) to my order & ship to Australia (as inexpensively as possible) if you'll cover my cost.

The 4.8v 3753-H is 1.8 amps, and the 3704-L is ~0.8 amps IIRC. Both come paired in a single pack, and are currently on sale for US$8 or so. It's possible that they may run well on 5 cells vs. the 4 cells in this build for a whiter beam, which is something that I'm interested in trying. I'd expect less bulb life, but from what I've read of the Pelican bulbs here on CPF, they are pretty high quality, and I'm pretty certain these aren't driven hard on 4 cells. 

Edit: The 3753-H *CANNOT* be run on 5xC, I tried one and it insta-flashed. 

It's possible that the 3704-L might be overall a better bet for general use on alkaline cells (this bulb should be pretty comparable to the Xenon MagnumStar), I see from the Duracell graphs that the watt-hours from alkaline 'C's are really dropping off at a 1.8 amp drain rate. NiMH is definitely be the way to go for high-drain applications like the -H bulb.

Edit #2: The 3704-L (included in the 3754 package) isn't a very good performer at all, post # 15 has more info.


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## Howecollc (Oct 27, 2009)

Kestrel said:


> I plan on ordering a bunch of assorted Pelican bulbs in a few days


Any chance you're planning on experimenting with the *Pelican 3804 Big D Alkaline Bulb *(2 pack of 8 watt at 7.2v = 1.10A bulbs)? The light is out of production, but the bulbs continue to be available. Not many easy options for overdrive, but an interesting 7.2v bulb falling between the 6 cell MagStar and Pelican 3853-L for current draw.

Somehow, the 3753-H has escaped my notice until now. I wonder how similar it is to the Ikelite 0042.55 bulb? Possibly it would be less demanding on the F cells of a 6 volt lantern battery than on the C alkalines?


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## trampasc (Oct 27, 2009)

Newbie question:
Where can I buy those bulbs and how do you make the new modified spring?


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## Kestrel (Oct 27, 2009)

trampasc said:


> Newbie question:
> Where can I buy those bulbs and how do you make the new modified spring?


The Pelican 3754 pack (3753-H & 3704-L), currently on sale:
https://www.storesonline.com/site/529271/product/Pelican%20%203754%20Bulb%20Set
A CPF thread pointing to the source above:
http://www.cpfmarketplace.com/mp/showthread.php?t=199685

I made the shortened spring from an El Cheapo 2D flashlight so I wouldn't have to chop up the Mag spring.

*Edit: Just a FYI on the stock # of this bulb. I found that the Pelican info for this item is a little odd, the offical Pelican stock # is 3754, the cardboard backing says 3754, but 3753-H is printed on my -H bulb, and 3704-L is printed on my -L bulb. Just a heads-up if someone is shopping for these bulbs.*


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## mvyrmnd (Oct 27, 2009)

Kestrel, PM sent.

FWIW, to fit 4C's in my 3D Mag, I just turned the original spring upside-down. Seems to work perfectly well, just no room for spare bulb anymore.


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## Kestrel (Nov 10, 2009)

Another comparison, this one on a Mag 4D:

The stock Mag 4D bulb, not bad really. The standard ‘Mag’ artifacts:










The 3704-L (comes in the pack with the 3753-H), not an improvement at all, with even more artifacts than the Mag bulb: (BTW I have not photographed this bulb yet, I haven't really felt the need. It looks sort of like the 3753-H but with a less-uniform glass envelope and a wimpier filament.)










The 3753-H, somewhat of an improvement over the stock Mag 4D, I was hoping for a little more difference, to tell the truth. Overall, a brighter hotspot to my eye and the focused hotspot has less of the usual 'batwing' of the Mag filament, though:











*Blowing up two of the pics, before & after:*

*Stock Mag 4D bulb*__________________ *Pelican 3753-H*








I then tried the 3753-H on *5xC*, but unfortunately it ‘flashed’. Apparently 4 cells is the limit for this bulb. 

BTW, question, this Mag 4-cell bulb is embossed "Mag*+* 4 cell HK 1K2". The Mag 3-cell bulb from the beginning of this thread is "Mag 3 cell HK 18K". Does anybody have an idea if the 4 cell bulb would be a Xenon (MagnumStar), or just a Krypton (WhiteStar)? This 'stock' Mag 4D ~0.8A didn't do that bad at all compared to this Pelican 4.8v 1.8A Xenon, and appeared to outperform the Pelican 4.8v 0.8A Xenon bulb (the 3704-L).


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## mvyrmnd (Nov 14, 2009)

So, would the Mag fitted with a 3753-H be a "Shout of the Pelican?"

It certainly doesn't roar, but it's yelling fairly loudly...


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## Howecollc (Nov 14, 2009)

Kestrel said:


> BTW, question, this Mag 4-cell bulb is embossed "Mag*+* 4 cell HK 1K2". The Mag 3-cell bulb from the beginning of this thread is "Mag 3 cell HK 18K". Does anybody have an idea if the 4 cell bulb would be a Xenon (MagnumStar), or just a Krypton (WhiteStar)? This 'stock' Mag 4D ~0.8A didn't do that bad at all compared to this Pelican 4.8v 1.8A Xenon, and appeared to outperform the Pelican 4.8v 0.8A Xenon bulb.


All MagnumStar Xenons I have seen have a glass envelope that is shaped like the Pelican bulb on the right in the picture below. I don't know if they have always been shaped this way, but I have one that I bought from a small hardware store that was old enough to not have the standard lower edge frosted glass, yet it was still the same narrow, straight walled shape. All WhiteStar Kryptons and all early model standard Krypton Mag bulbs have the globe shaped glass envelope of the left-most Mag bulb in the picture below. 

1.8 amps is possibly too much current draw for alkaline C cells, hence the less than expected difference between the 4 cell Mag and the 3753-H.


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## Kestrel (Nov 14, 2009)

mvyrmnd said:


> So, would the Mag fitted with a 3753-H be a "Shout of the Pelican?"
> It certainly doesn't roar, but it's yelling fairly loudly...


LOL, IMO the ROP gets its name partially because it is so popular on CPF. What I've done is just a pipsqueak hotwire that doesn't even use high-performance cells. Maybe if this bulb catches on, MOP for Murmor of the Pelican (?) :green:, but that would probably just confuse the orange-peel reflector folks. :tinfoil: 


Howecollc said:


> All MagnumStar Xenons I have seen have a glass envelope that is shaped like the Pelican bulb on the right in the picture below. I don't know if they have always been shaped this way, but I have one that I bought from a small hardware store that was old enough to not have the standard lower edge frosted glass, yet it was still the same narrow, straight walled shape. All WhiteStar Kryptons and all early model standard Krypton Mag bulbs have the globe shaped glass envelope of the left-most Mag bulb in the picture below.


OK, this stock bulb that I took out of the Mag 4D probably isn't the upgraded Xenon bulb then, its glass envelope looks identical to the stock Krypton Mag bubs. Thanks.


Howecollc said:


> 1.8 amps is possibly too much current draw for alkaline C cells, hence the less than expected difference between the 4 cell Mag and the 3753-H.


Good point. (BTW it's alkaline D cells instead of alkaline C's for my more-recent 4D comparison tho.) I will send a free :twothumbs to the first person who posts in this thread using this bulb with 4x NiMH (preferably C's or D's) and compares it to 4x Alkalines (and the stock Mag 4D Bulb) with the same host/reflector.


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## mvyrmnd (Nov 14, 2009)

Well, how about "Squawk of the Pelican"


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## Kestrel (Nov 14, 2009)

LOL, now that name I like a lot. :thumbsup:


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## mvyrmnd (Nov 14, 2009)

Now if we can just get this thread added to the Mag Mods Sticky, It'll be official!

All of history will know of Kestrel, creator of the SOtP! (just to keep the reflector guys happy )


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## poormanq45 (Nov 15, 2009)

Maybe the pictures arn't showing the whole story, but it appears that the Pelican bulb is very close to the Mag bulb. 

Is that because the Alkalines arn't able to deliver the current?


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## DM51 (Nov 15, 2009)

mvyrmnd said:


> Well, how about "Squawk of the Pelican"





Kestrel said:


> LOL, now that name I like a lot





mvyrmnd said:


> Now if we can just get this thread added to the Mag Mods Sticky, It'll be official!
> 
> All of history will know of Kestrel, creator of the SOtP! (just to keep the reflector guys happy )


Well, first we need to know what type of noise these birds actually make, lol. Personally, I've never heard a pelican roar, but it's in the CPF lexicon, so that's good enough for me.

When they aren't roaring, do they croak, squeak, groan, sigh, yell, bellow, grunt, or what? From what I've seen of them, their mouths are usually full of fish, so the best I can imagine them achieving would be a sort of gurgle.


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## Kestrel (Nov 15, 2009)

poormanq45 said:


> Maybe the pictures arn't showing the whole story, but it appears that the Pelican bulb is very close to the Mag bulb.
> 
> Is that because the Alkalines arn't able to deliver the current?


Yes, I imagine that I'm not getting quite the ~1.8 amps out of 4x Alkaline D's than would be possible from NiMH C's or D's (that I don't have). I don't have a way to measure current at the tailcap, so :shrug:. I can leave it up to others to evaluate this bulb with 4x NiMH, these aren't even my lights that I've been posting about.  I'm pretty certain that this bulb has more potential on NiMH.

Outside in more of a long-distance situation, this bulb does pretty well compared to the Mag bulb - I think part of it is the filament shape permitting a tighter hotspot. Anyway, just a guess, I admit I'm very much an incan newbie.


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## mvyrmnd (Nov 15, 2009)

Kestrel said:


> Yes, I imagine that I'm not getting quite the ~1.8 amps out of 4x Alkaline D's than would be possible from NiMH C's or D's (that I don't have). I don't have a way to measure current at the tailcap, so :shrug:. I can leave it up to others to evaluate this bulb with 4x NiMH, these aren't even my lights that I've been posting about.  I'm pretty certain that this bulb has more potential on NiMH.
> 
> Outside in more of a long-distance situation, this bulb does pretty well compared to the Mag bulb - I think part of it is the filament shape permitting a tighter hotspot. Anyway, just a guess, I admit I'm very much an incan newbie.



As soon as my bulbs arrive I'll do some measurements, and I plan to use them on NiMH's anyway, so I can do some comparisons.


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## mvyrmnd (Nov 15, 2009)

DM51 said:


> Well, first we need to know what type of noise these birds actually make, lol. Personally, I've never heard a pelican roar, but it's in the CPF lexicon, so that's good enough for me.
> 
> When they aren't roaring, do they croak, squeak, groan, sigh, yell, bellow, grunt, or what? From what I've seen of them, their mouths are usually full of fish, so the best I can imagine them achieving would be a sort of gurgle.



Well, as it turns out, they make a grunting/growling sound....

Growl of the Pelican?


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## poormanq45 (Nov 15, 2009)

I wonder how this would compare to the MagnumStar Xenon bulbs from mag. You said the original kypton bulb was being used, right?


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## Kestrel (Nov 15, 2009)

poormanq45 said:


> I wonder how this would compare to the MagnumStar Xenon bulbs from mag. You said the original kypton bulb was being used, right?


Yes, this Xenon 3753-H @ ~1.8A should definitely outperform the Mag Xenon bulbs @ ~0.8A (amperage for Mag Xenons per Howecollc) for the same voltages (~4.8v or so). I expect that this bulb really does need NiMH to really come into its own.


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## mvyrmnd (Nov 24, 2009)

Thanks to Kestrel, my GOP bulbs arrived in the mail today. I'll post some beamshots and measurements later...


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## Kestrel (Nov 24, 2009)

mvyrmnd said:


> Thanks to Kestrel, my GOP bulbs arrived in the mail today. I'll post some beamshots and measurements later...


I dunno, I like 'squawk' better - that way it doesn't sound like a political party over here... :tinfoil:
Very interested to see this bulb on 4x NiMH.


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## mvyrmnd (Nov 24, 2009)

I just googled GOP. From now on I'll use squawk... If I was American, I certainly wouldn't be Republican.

We're back to SOtP.


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## mvyrmnd (Nov 25, 2009)

OK,

It's finally dark here at 9pm, and I've got some comparison shots and some measurements. No NiMH batteries yet, though.

First up, a shot of the stock Mag 3D, on fresh batteries.







The tin wall is about 5m away. The Mag is at its tightest focus. The Camera is at 1/4sec, 3.5F, infinite focus.

Now, The Mag SOtP:






Same camera settings. Bulb is at 6.15V/1.72A. Much whiter and brighter than stock. On fresh alkaline C Cells.

For such a simple mod, it's a pretty good improvement.


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## caltemus (Jan 3, 2010)

Would the 3753-H work with a 4xD configuration or would it flash like the 5xC? What about using Li-Ions or Eneloops?


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## Kestrel (Jan 3, 2010)

caltemus said:


> Would the 3753-H work with a 4xD configuration or would it flash like the 5xC? What about using Li-Ions or Eneloops?


No problems at all with 4xD alkaline, as tested here in my post #15. I'm very confident that 4xNiMH of any capacity will be just fine, I've ran it for an hour on 4x AA NiMH and I'm sure that the slightly less voltage sag of 4x D NiMH wouldn't be any problem as well. 4x Eneloop would also be just fine.

I do have my doubts on how much this bulb outperforms the less-expensive 4-cell Magnumstar bulb (which I have not tested) while on alkalines - however, with the higher-current-capability of NiMH chemistry, this bulb should really be able to stretch its legs.

2x LiIon, now you're in ROP territory though, 2x LiIon is great for the 3854 and 2x IMR is great for the 3853. Better bulbs overall, a huge step-up in performance, other threads cover ROPs very well. ROPs do need more upgrade parts though - reflector & lens for starters.


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## caltemus (Jan 3, 2010)

I must not have read closely, I thought that you used a 3D. Thanks for the info! I look forward to the upgrade.


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## mvyrmnd (Jan 31, 2010)

Hey Kestrel...

How do you think the 3753-H would go on 4x NiZn batteries?

You said the bulb would flash on 5 alkalikes (7.5v) but 4 AA NiZn's in C-size adapters would be 6.4v. If it works, it should be nice and bright.

I'm not sure if i want to waste my frosted bulb with the experiment...


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## Kestrel (Jan 31, 2010)

mvyrmnd said:


> How do you think the 3753-H would go on 4x NiZn batteries?
> You said the bulb would flash on 5 alkalines (7.5v) but 4 AA NiZn's in C-size adapters would be 6.4v. If it works, it should be nice and bright.


Sorry, no idea. I do know that I'd greatly prefer 4x *C* LSD NiMH (4500 mAh) to 4x *AA* NiZn tho.


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## mvyrmnd (Jan 31, 2010)

Yeah, I'm well aware of the runtime I'd be sacrificing, but that's the price you pay for lumens, huh?


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## Chrontius (Feb 10, 2010)

And really, someone (Fivemega) will put out a 4s3p battery carrier if that sort of thing catches on.


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## mvyrmnd (Feb 10, 2010)

Chrontius said:


> And really, someone (Fivemega) will put out a 4s3p battery carrier if that sort of thing catches on.



I'll be the first one to buy it if he does


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## Lawyerman (Feb 11, 2010)

I'm sure you guys are going to think I'm as dumb as a post but why go from 3 d's to 4 c's? 

What's the benefit in doing that? Is it greater runtime for equal voltage?


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## Kestrel (Feb 11, 2010)

Lawyerman said:


> why go from 3 d's to 4 c's?
> What's the benefit in doing that? Is it greater runtime for equal voltage?


Hey there, not a problem. It's really about increasing the voltage to get higher outputs at comparable drive currrents, as output wattage = volts X amps.

The thing is that to get decent outputs from incans you need a decent voltage (there have been a very few low voltage, relatively-high current bulbs, but I gather that performance isn't all that great from them - FiveMega knows more on this). Going from 3D to 4C takes the voltage of the cell stack from ~3.6v to ~4.8v, at which point this nice Pelican 4.8v bulb can be used. The only commonly-available PR-base Xenon bulb for 3 cells is the 0.8 amp, 3-cell MagnumStar bulb, which has far less output (~*80 lumens*).

If someone made a 1.8 amp, 3-cell Xenon bulb, 3xD _might_ be a comparable choice to 4xC due to the greater overall stored energy of 3xD?

BTW this is the brightest 4-cell PR-base bulb I know of (~*250 lumens*). Going up more voltage to 7.2v gets you to the fantastic 2.0 amp Pelican 3854-L, and ~*500 bulb lumens*. So the main goal for the low-end incans is to get to a decent voltage.

So my back-of-the-envelope estimates for making an efficiency comparison:

*3.6v*: 0.8 amp, 3-cell MagnumStar bulb: ~80 lumens, ~3.5 watts for an efficiency of ~*20-25 lumens per watt *
*4.8v*: 1.8 amp, 4-cell Pelican 3753-H: ~250 lumens, ~8.5 watts for an efficiency of ~*30 lumens per watt*
*7.2v*: 2.0 amp, '6-cell' (yes I know it's not officially a 6-cell, but everyone here seems to use it that way ;-)) Pelican 3854-L: ~500 lumens, ~15 watts for an efficiency of ~*30-35 lumens per watt*
(These calcs are just estimates, the voltages are a particularly difficult comparison due to voltage sag, cell chemistry, etc)

So we are getting overall better performance by increasing voltages (for bulbs of higher-rated voltage) as well as increasing the drive currents.

Hope that helps? I admit I'm pretty new to the incans tho.


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## Lawyerman (Feb 11, 2010)

Basically, it allows you to use a much higher lumen bulb in pretty much the same space envelope. Got it.


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## alpg88 (Feb 11, 2010)

MorePower said:


> You could use the constant power graphs to develop more accurate runtime estimates if you'd like.


 
or you can go with real life test, just run it and time it.


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