NEW DATA****Surefire P91 tested by MrGman @ CPF meet

[bigchelis]

Finally MrGman got to test the P91.

With 2 IMR 16340's and a non-UCL lens.....It was a Leupold hosts.
380 plus out the front lumens!!!!!!!!





EDIT: The Surefire P91 Lamp w/ 2 AW 17670's topped off (4.2v EACH) and my Surefire 6P hosts w/ UCL lens and Solarforce 18650 extention.


SureFire P91_____________UCL in SureFire 6P_____2XAW17670,_466.0_____1 sec______,

 

[csshih]

Re: Surefire P91 tested by MrGman @ CPF meet

:O

I'm running one of those!

how old were those 16340s? I suspect mine isn't as bright anymore.

 

[bigchelis]

Re: Surefire P91 tested by MrGman @ CPF meet

:O

I'm running one of those!

how old were those 16340s? I suspect mine isn't as bright anymore.

The light wasn't mine, thus I don't know how old they were.

P.S. MrGman took the sphere to the San Jose CPF meet and it would have been cool to see what some of your lights make. Maybe next time!!!:candle:

I think the P91 with 2 IMR 18650's and a UCL lens host will be at and over 400 out the front lumens!!!!!!!!! I had the Lumens Factory D26 500 lumen drop-in. With 2 IMR 16340's it did 270 out the front. While doing outdoor beam shoots the P91 was clearly brighter and others there could see the difference too. I guess Surefire lumens are super underrated with the P91.

bigchelis

 

[bigchelis]

Re: Surefire P91 tested by MrGman @ CPF meet

Does anyone know 100%, if the Surefire P91 will go with 2 IMR 18650?

 

[Outdoors Fanatic]

Re: Surefire P91 tested by MrGman @ CPF meet

Does anyone know 100%, if the Surefire P91 will go with 2 IMR 18650?

I'd say it is safer and much cheaper to run the IMR-9 than the P91 on those batteries.

 

[fivemega]

Re: Surefire P91 tested by MrGman @ CPF meet

Finally MrGman got to test the P91.

With 2 IMR 16340's and a non-UCL lens.....


380 plus out the front lumens!!!!!!!!

It would be more helpfull for others if you provide more information about your set up such as battery voltage prior to test, type of switch and host.
AW's soft start switch with 2 protected 18650 works fine with P91 or 1794.

 

[325addict]

Re: Surefire P91 tested by MrGman @ CPF meet

I only tested a P91 on two 17500 Ultrafire batteries (yes, I know, this is not safe, so I did it only a few seconds) but MAAAAAAN, a WALL of light came out.... much brighter than the (already not bad) P90....

One way to guess if the P91 will go on two 18650s:

1. Take three brand new, reputable-branded CR123As,
2. take a piece of tubing, 2.5X the length of the 3 batteries,
3. put in batteries, connect the P91, using a separate piece of wire,
4. take one helper, he should measure voltage of the batteries now :thinking:

This test should better be performed pretty quick, otherwise your fingers holding the P91 will burn :green:

If the voltage measured is around 7.4V then it should be safe to use two 18650s. Is the voltage lower, eg 6.8V or so, then DON'T EVEN TRY to use two fully charged 18650s: the P91 will almost certainly instaflash....

It's all about the design-voltage of the lamp: it has been designed to operate on three primary CR123s. The voltage three brand new of them deliver, should be no problem for the P91. Any higher means a severe risk of instaflashing it.
I personally would judge 0.2V lower than 7.4V the point of danger. So if you read less than 7.2V in this test, I would not try to use 18650s.


Hope this helps.

Timmo.

 

[Outdoors Fanatic]

Re: Surefire P91 tested by MrGman @ CPF meet

I only tested a P91 on two 17500 Ultrafire batteries (yes, I know, this is not safe, so I did it only a few seconds) but MAAAAAAN, a WALL of light came out.... much brighter than the (already not bad) P90....

One way to guess if the P91 will go on two 18650s:

1. Take three brand new, reputable-branded CR123As,
2. take a piece of tubing, 2.5X the length of the 3 batteries,
3. put in batteries, connect the P91, using a separate piece of wire,
4. take one helper, he should measure voltage of the batteries now :thinking:

This test should better be performed pretty quick, otherwise your fingers holding the P91 will burn :green:

If the voltage measured is around 7.4V then it should be safe to use two 18650s. Is the voltage lower, eg 6.8V or so, then DON'T EVEN TRY to use two fully charged 18650s: the P91 will almost certainly instaflash....

It's all about the design-voltage of the lamp: it has been designed to operate on three primary CR123s. The voltage three brand new of them deliver, should be no problem for the P91. Any higher means a severe risk of instaflashing it.
I personally would judge 0.2V lower than 7.4V the point of danger. So if you read less than 7.2V in this test, I would not try to use 18650s.


Hope this helps.

Timmo.

IMR-18650s are not like regular 18650 li-ion batteries at all. Those will definitely kill a P91.

 

[bigchelis]

Re: Surefire P91 tested by MrGman @ CPF meet

It would be more helpfull for others if you provide more information about your set up such as battery voltage prior to test, type of switch and host.
AW's soft start switch with 2 protected 18650 works fine with P91 or 1794.

It was a Leopold P60 light. It looks like a 6P. The CPF member had 2 IMR 16340's in it and unfortunately that is all I know. I guess when he didn't want to try it with 2 IMR 18650's he had a good reason..

 

[bigchelis]

Re: Surefire P91 tested by MrGman @ CPF meet

I'd say it is safer and much cheaper to run the IMR-9 than the P91 on those batteries.

The IMR-9 was mine and I do know the set-up.

It was my Surefire 6P with UCL lens and my tailcap has a clickie from DX donor installed. I assume a twistie might have been a better choice. I had topped off 2 IMR 16340's and it did 270 out the front. While the P91 did more than 100 out the front with no UCL lens.:duh2:


Fivemega,
I will try and get a soft-start and a P91 by this week and try it with 2 IMR 18650's and my Surefire 6P hosts mentioned above. Then I can ask MrGman to see what it will do.

 

[Bullzeyebill]

Re: Surefire P91 tested by MrGman @ CPF meet

Fivemega,
I will try and get a soft-start and a P91 by this week and try it with 2 IMR 18650's and my Surefire 6P hosts mentioned above. Then I can ask MrGman to see what it will do.

Lower your voices guys. No need to shout. :naughty:

Bill

 

[325addict]

Re: Surefire P91 tested by MrGman @ CPF meet

@ outdoors fanatic:

yes, I know, They don't have the slightest difficulties with these high currents. But, even a "regular" 18650 will have no problems with a current of 2.7 Amps..... I think, the difference will become evident with 5 Amps or so.... however, the peak current capabilities of the IMR 18650 will kill the P91 I'm afraid. A regular one will sag in during start-up, an IMR hardly will do so, causing it to instaflash

What do you think: will it survive using an AW soft-starter??

Timmo.

 

[bigchelis]

Re: Surefire P91 tested by MrGman @ CPF meet

@ outdoors fanatic:

yes, I know, They don't have the slightest difficulties with these high currents. But, even a "regular" 18650 will have no problems with a current of 2.7 Amps..... I think, the difference will become evident with 5 Amps or so.... however, the peak current capabilities of the IMR 18650 will kill the P91 I'm afraid. A regular one will sag in during start-up, an IMR hardly will do so, causing it to instaflash

What do you think: will it survive using an AW soft-starter??

Timmo.

Timmo,
Thanks, I should have asked this question before regarding instaflash with AW soft-starter!!

My goal is to get at least 400 out the front lumens with the P91. I think its possible, but only one way to find out.

 

[Outdoors Fanatic]

Re: Surefire P91 tested by MrGman @ CPF meet

Timmo,
Thanks, I should have asked this question before regarding instaflash with AW soft-starter!!

My goal is to get at least 400 out the front lumens with the P91. I think its possible, but only one way to find out.

That's why I've said: "Why not the IMR-9?"

 

[bigchelis]

Re: Surefire P91 tested by MrGman @ CPF meet

That's why I've said: "Why not the IMR-9?"

Because the IMR9 did 270 lumens with 2 IMR cells and I want to see just for kicks if I can get the P91 to do 400 out the front. I do agree that the IMR9 is more practical because I don't need to worry about instaflash or purchasing a soft-start switch.

When I get home I will measure the current of my IMR9 D26 drop-in w/those same 2 IMR 16340's to measure the current vs. 2 IMR 18650's. I bet the IMR9 will offer longer runtimes which makes it more practical for my 30 to 45 minute walks after dinner.

Also,
My first Surefire was a 9P with the P91 lamp and primaries. It was what got me into this hobby and I always wondered why it seemed so much brighter than 200 lumens. The 9P is in my avatar w/my 1911.

bigchelis

 

[kramer5150]

Re: Surefire P91 tested by MrGman @ CPF meet

No doubt that thing was BRIGHT. One of the brighter, small lights at the meet.
That Leopold P60 host is REALLY (really) well made. It had a really nice typeIII finish and some solid heft and mass to it. It actually made my M2 feel a little thin and lightweight by comparison.

 

[Justin Case]

Re: Surefire P91 tested by MrGman @ CPF meet

Looks like the estimates here are reasonably good:

MDs Lithium-Ion > Incandescent guide + compatability/comparison chart
http://candlepowerforums.com/vb/showthread.php?t=161536

Cell configuration: 2xIMR16340
SF P91: 20W, 300 - 125 lumen in 10 minutes

Cell configuration: 2x18500
SF P91: 20W, 320 - 170 lumen in 28 minutes

Cell configuration: 2x17670
SF P91: 20W, 330 - 175 lumen in 31 minutes

Cell configuration: 2x18650
SF P91: 20W, 360 - 215 lumen in 43 minutes

Cell configuration: 2xIMR18650
(P91 and FM1794 should be avoided, will reduce bulb life substantially, very likely to just instaflash the bulb)

Also nice to know that my MN11 driven by 2xIMR16340 is also probably in the 380 lumen range on startup with fresh cells.

 

[mdocod]

Re: Surefire P91 tested by MrGman @ CPF meet

Not bad for paper guesstimates if I may humbly say....

I've long suspected the P91 to be brighter than I had estimated but was fearful to "go there" for fear of ridicule so leaned on the side of conservatism on the bulb. I based the original estimates starting with SFs "200" lumen claim and extrapolating up from there based on the expected level of overdrive on li-ion cells... Obviously the 200 lumen claim was under-rated on CR123s

Check this out though...

First solve for X..

(X/6.6)^0.55=1.085

x/6.6=1.16

~7.656

6.6V would be the estimated Vbulb to achieve the ~2.45-2.50A measured on P91s when driven by CR123s. Work backwards to identify an estimated Vbulb to achieve the ~2.7A that is measured by most folks when running 2xli-ion cells.

Now, (7.656/6.6)^2.9=1.538

I think it's safe to say that the P91 is truly closer to 260 torch lumen on CR123s working backwards on this.

SureFire might test their bulbs, but I suspect they are more interested in product placement on paper, but they choose to de-rate rather than inflate numbers to get those nice round numbers and proper product image....

MN11 and MN16 should perform basically the same, explains a lot really...

---------------------------

Thank you guys for the real world testing of this bulb. The P91 and 1794 have both recently been through some real testing that, in my opinion, gives them some serious leverage to hold their ground against LEDs for a little while longer

 

[Justin Case]

Re: Surefire P91 tested by MrGman @ CPF meet

Ok, I finally figured out what the host light was -- LEUPOLD.

They use a sapphire window for their flashlights. Uncoated, sapphire light transmission is in the 85% range, mainly due to surface reflections. Single-layer coated with magnesium fluoride, light transmission can be 98%. It would be good to know if Leupold coats their sapphire or not. But since they are primarily an optics company, odds might be that they do coat the sapphire with MgF2. Thus, going to a UCL might not produce any gain in lumens. In fact, it might go down since sapphire windows can be made thinner than glass windows for the same strength.

 

[gswitter]

Re: Surefire P91 tested by MrGman @ CPF meet

Damn. When we were talking about it, I didn't realize bigchelis had the IMR 18650s with him at the BBQ. I knew he had the tube, and if he didn't already have the soft start switch, we at least had the parts to assemble one, but I thought he was suggesting testing it with 18650 LiCo cells. I'd also be curious to try that particular lamp on three primaries. Oh, well... next time.

My hesitancy to try the P91 on the 18650 LiMn cells is mainly from the posts of others' tests with known bulbs. WA01111s and 1185s are pretty robust with 2x 18650 LiCo cells, and I've had no trouble with them on IMR16340s, even fresh off the Pila IBC charger (usually 4.21V-4.22V). But as I recall from posts by ElectronGuru and a few others, neither the 1111 nor the 1185 can handle the bigger LiMn cells, even with a soft start. Given the optiion, I'd try the P91 on a pair of IMR18500s first.

As far as the set-up that was tested over the weekend. The P91 was purchased new back in December, and had less than ten minutes on it. The IMR16340s were on their third or fourth cycle, and had probably never been run town below 50%. They were fleshly charged by the Pila charger the night before, and both measured 4.21V off the charger.

I'm glad I had another chance to show off the Leupold/P91/IMR16340. The incompatibility with non-Surefire, aftermarket P60 drop-ins is a tough point to get past, but the pre-configured MX-121 package compares quite favorably with similar lights from Surefire when you consider the price, features and quality.