16650 + P60 lamp assembly = ?

Megalamuffin

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Hey folks, has anyone used 16650’s with an incan p60 lamp assembly? Does it work well?

I have orbtronic 16650’s and a 6p that works great with a malkoff drop in, but I want to use that original p60 incan sometimes too. The p60 goes through primary cells fast so if I could use my rechargeables without issue that would be awesome. The 16650 voltage should be fine from what I understand but are there other concerns to be aware of?
 

Katherine Alicia

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I run an 18650 with a 6v P60 incan dropin without a problem at all, I also have 21700 version too that uses the same P60 module, a 16650 will be just fine. though you can buy 3.7v P60 incan dropins as well ;)
 

Grijon

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I have a Surefire 6P with stock P60 that I have run for quite a few hours (perhaps a dozen or more) on 16650 power; so far there have been no detrimental effects.

Be aware that it will be much dimmer than primary power (pun intended), but it will also comfortably run 2 hours per charge on a 2600mAh cell.

This is my personal first-hand experience.
 

Owen

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There are no concerns, it'll just be significantly dimmer, with lower color temp, and constantly getting worse. You're not going to hurt anything, but it'll suck, like every underdriven incan.
 

Katherine Alicia

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I don`t find it anywhere near "dim" and the color temp`s roughly 3000k, it certainly Doesn`t "suck"! Ceiling bounce in a 13x13 room will provide more than a enough light to be able to read anywhere in the room.
 

fivemega

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Single 16650 or 18650 will underdrive a P60 lamp but not that bad.
Single IMR will do slightly better because IMRs hold the voltage slightly higher.
I use
2 parallel 18650 which holds higher voltage very well under load of P60 which is about 1.2Amp and runs long time per charge. This setup works very well with P61
 

Stress_Test

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It's strange, I see this question come up on a fairly regular basis, but I don't think anyone has ever posted any example photos. So I'll give it a whirl here.

First, I needed something to compare with, which I own, and also had been tested. CPF member MrGman did extensive testing with an actual integration sphere, including tests of Quark Mini and Preon lights:

XAOx6hDl.jpg


As you can see, the Mini and Preon are both apx. 20 lumens on the medium mode. Just by eye, I figured the P60 on a single Li-ion was somewhere in the 30 lumen range, maybe as much as 40. On a single 18650 (not fresh), at 4.08 volts unloaded, I measured an initial current of a bit over 0.9 amps. This was in a SolarForce host, measured from the body to the battery (tailcap bypassed).

So, assuming that under load, the voltage drops to 3.7 volts at that current measurement, the wattage would be about 3.3 watts. Assuming a poor efficiency of only 10 lumens per watt (since it's underdriven), that should still put the lumen output in the 30-ish lumen range.

Since I don't have an integration sphere or a light meter, this was the best I could think up. A plastic jug filled with water, and the light shining down through the cap of the jug. The cap diffuses the beam to eliminate effects of thrower vs. flooder. The water and plastic of the jug evenly distribute the light. Then I take photos with my camera, locked to the same settings for each shot, to allow the brightness of the image to be compared. All brightness test photos were shot in black-and-white mode on the camera to eliminate the effects of color on brightness perception.

The SF host may be at a slight disadvantage, since (1) the crenelated bezel allows a tiny bit of leakage out the sides, and (2) the larger head diameter may be causing some light to hit the threads of the jug and not be distributed into the water as well. Probably negligible for the most part though.

Click the thumbnail images for a larger size; with a photo open in each tab of your browser, it allows easy A/B comparison.

First, the Mini AA on medium:



Now the Preon on medium:


You can see that the Mini and Preon are essentially the same output, confirming the results of the table above.


And now the P60 x 18650 SolarForce:



When you open these in separate tabs and click from one to the other, you can tell that the P60 is noticeably brighter than the 20 lumen modes on the Mini and Preon. Now for grins, let's check the max output of the Mini AA, which is somewhere in the mid-60 lumens range according to the table above.

Mini AA, high mode:



As expected, it's noticeably brighter than the P60x18650 combo, but perhaps not as much as you might think.

Now let's look at color temperature. An under-driven incan will typically have a lower (warmer) color temp, right? Let's compare the P60x18650 to a couple of LED lights, on a "still life" setup. I don't have a color checker card, but I've found that food product boxes are good for this sort of thing, since they tend to be bright and colorful.

The camera is set to a white-balance color temp of 3000 K, trying to hit a happy medium between light sources. These photos were shot in raw mode, then converted to jpg on a PC, to make sure there was no unexpected variation from shot to shot caused by the camera jpg conversion.

First, a Cree PAR-style LED lamp, 2700K, shining upwards at the white ceiling to illuminate the scene. The lamp is just off-camera about 2 feet to the left. The door in the background is glossy white.


As you'd expect, the scene appears just slightly warm since the light source is 2700K vs the camera setting at 3000K.

Now, a Quark Mini AA Warm (exact color temp unknown)


The whites look just about true white in this shot, indicating the Mini color temp must be very close to 3000K. There's just a hint of ugly color tint though. You would hardly notice it unless you were doing direct comparisons to another light source.

Now the P60. Slight disclaimer: it was really hard to evenly light this scene with the spotlight beam of the P60 and not get it too dark, or have weird shadows, or blown out. This was the best I could do after at least a half-dozen attempts. I had to push it about 1 stop brighter in post processing, so that the overall brightness would look similar to the other scenes. Shouldn't affect the color temp though. The ISO was set the same for all shots.


This looks VERY close to true white, indicating the P60 is pretty much bang-on 3000K for all practical purposes. Also, if you do a direct A/B compare of this image to the Mini-Warm, the ugly greenish tint of the Mini becomes much more apparent. On a personal note, I've found that almost all photos I've taken under LED light sources have issues with tint. It can be a real nightmare to correct if there are multiple LED lights with different tints. The worst I ran into was a highbay lit by Cree parking-lot area light assemblies. Despite being all the same product, there was enough tint variation to give me fits trying to make the whites in the scene look somewhat normal.

If I was a pro photographer, I think I'd still be using incan lights in some situations since there appears to be less issue with tint, and all you have to do is set the camera white-balance to whatever Kelvin value you want to make the scene warm, neutral, or cool. I was surprised by how nice the colors look in the P60 lit scene, despite being underdriven.

So there you have it. The P60 on a single Li-Ion is definitely viable if you want a lower output, longer running incan using a single rechargeable.
 

ampdude

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I don't know, but I suspect the xenon-halogen cycle will not be as effective when under driving that lamp, although it's not a huge under drive.
 

Owen

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I don't know, but I suspect the xenon-halogen cycle will not be as effective when under driving that lamp, although it's not a huge under drive.
I hadn't even thought in terms of bulb life, and have no idea whether it would make much difference or not, but based on the rest of the discussion, you probably just went over some heads.

You were just happy for the unexpected opportunity to throw a tidbit like that out there, weren't you?
Kind of like I was happy to see it:D
I think this means we're getting old...
 

Stress_Test

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For anyone who's never heard of the halogen cycle, I did a quick google search and found this page (by Zeiss and Florida State U.) that gives a explanation that's to the point and not a 30 page pdf.

http://zeiss-campus.magnet.fsu.edu/tutorials/halogencycle/indexflash.html

My added comments are mine based on my own understanding, but I'm NOT an expert. (chemistry was my worst subject)

The punchline (one of them anyway) is this:

Thus, vaporized tungsten reacts with hydrogen bromide to form gaseous halides that are subsequently re-deposited onto cooler areas of the filament rather than being slowly accumulated on the inner walls of the envelope.

So, without the halogen cycle process, you get the cloudy dark grey gunk on the inside of the bulb. I've seen some extreme examples on 500 watt Edison screw in bulbs.

The idea that under-driving a bulb interferes with the halogen cycle is based (I presume) on this statement from the article:

Once the envelope reaches a temperature of approximately 200 to 250° C (depending on the nature and amount of halogen vapor), the halogen regenerative cycle begins.

So if the bulb doesn't burn hot enough, the tungsten won't get re-deposited onto the filament, and it'll burn through faster. At least, that's how I interpret it.

Okay, so that's the theory side of it. Now in actual use, I haven't done any intentional endurance testing on a P60 to determine lifetime or other ill effects from using one Li-Ion.

All I know is that I haven't burned up the one that I've been using so far. I've got maybe 10 hours on it, at a wild guess??

And bottom line for me, if it shortens the bulb life by 20% it doesn't matter to me, since I would never use 123a primary batteries with a P60 anyway. The four P60 modules I have would be collecting dust otherwise, so I've got nothing to lose by using a Li-Ion. After I've blown the first three P60s I might put the last on the shelf for nostalgia, but I still haven't blown one yet.

And finally, here's a close-up photo of the P60 bulb I've been using. That glass looks pretty clean to me, aside from a few dust specs of course!

iKmGi6l.jpg
 

ampdude

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I hadn't even thought in terms of bulb life, and have no idea whether it would make much difference or not, but based on the rest of the discussion, you probably just went over some heads.

You were just happy for the unexpected opportunity to throw a tidbit like that out there, weren't you?
Kind of like I was happy to see it:D
I think this means we're getting old...

No, it's a pretty common discussion topic here in the incan forum. Bulb life, xenon halogen cycles. It probably won't make a huge difference though, which was where my thought process was going. I think that it has been recommended in the past to run a P60 for at least thirty seconds at a time at the minimum for the process to take place. With an under drive this might be more of an issue.
 

fivemega

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You can also use pair of these in 6P flashlight to power up P60 bulb.
Batteries drop the voltage under load and forwarded voltage to bulb will be almost same as primary lithium.

For me best rechargeable setup for this bulb is 4 Eneloops in
custom made body.
 

DRoc

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It’s probably more than that. Just an estimate. Early 2010s I stocked up. At that time I could get a p60 for 1$ and p61 for 10-15 usd
 
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