Surefire 9P + P91 Lamp Malfunction

[TonyW]

Hi Guys,

I've been using my Surefire 9P with P91 lamp and brand new standard Surefire CR123 battery recently but after 5-10 minutes it always goes off by itself and i'm really frustrated. If i leave it off for a while and turn it on again it'll still work but after another 5-10 minutes the same thing just happens.

Anyone able to provide some explanation? I noticed that the light generates quite a lot of heat and the sooner I turn it on again the sooner it'll go off. But Surefire have never said it's normal haven't they? Thanx guys.

 

[ampdude]

What is the ambient temperature where you are?

From what I understand the batteries can go into thermal shutdown after awhile, but I've never had it happen to me.

Holding the light in your hand will help things a bit, if you just turn it on and set it down on a desk, it will be too hot to touch after a few minutes running a P91.

 

[VillageIdiot]

How does this setup sound:

6P
P91
2xRCR123a 3.7v li-ion

Lumens, runtime?

 

[Bullzeyebill]

The 2+amp draw on the batteries is causing the shutdown. P91 is meant for short bursts of light. It is not meant to be an edc setup with long runtimes. Best to use the P90 for longs runs. Recommendation for use of P91 with Li-ions is an ok idea if you are using cells that have a fairly high capacity such as 17670, or 18650 (18670's).

Bill

 

[SureAddicted]

Hi Guys,

I've been using my Surefire 9P with P91 lamp and brand new standard Surefire CR123 battery recently but after 5-10 minutes it always goes off by itself and i'm really frustrated. If i leave it off for a while and turn it on again it'll still work but after another 5-10 minutes the same thing just happens.

The P91 only lasts (runtime) for 20 min.

 

[mdocod]

IIRC, it is a common problem for even SureFire CR123s to go into "thermal shutdown" when used on SureFires HOLA lamps, which draw ~2.5A from the cells. As others have said, SF HOLA lamps are really not intended for continuous use. The P91 will make the head of a 9P too hot to hold in just a few minutes in my experience, which means that top battery in the flashlight would be dealing with some serious heat.

If you need a flashlight with this level of output, but would like to be able to run it a little longer without problems, I would personally suggest picking up a FM 2x18650 body, a pair of AW protected 3.7V 18650s, and a LumensFactory EO-9.

The EO-9 on the 18650s is going to be pretty similar to the output of your P91 on CR123s, the size of the flashlight will be 1 cell longer (imagine a "12P"), and the runtime will be close to 1 hour. I would suggest limiting continuous runs to 10-20 minutes depending on ambient temps. The EO-9 will make a little less heat than the P91.

Alternatively, if you like the floody beam of the P91, but want to be able to run the thing continuously without restriction, install a M60WF from MalkOff (not sure if a flood version of the warm emitter is available yet, but this would be the best way to make a more endurance oriented flashlight).

Eric

 

[mdocod]

How does this setup sound:

6P
P91
2xRCR123a 3.7v li-ion

Lumens, runtime?

Sounds like a recipe for killing RCR123s.... Won't work with most protected ones anyways.

Please read the "li-ion incan guide/compatibility chart"
The link is in my sig line.

 

[TonyW]

Thank you everyone for all the info provided, you're the most helpful. And I'll surely try out some the configurations you suggested.

Tony

 

[Sgt. LED]

The HO-9 is really close to what you want too but isn't as tough on the cells.
Just saying...........

Also Gene is making warm flood models and they are awesome!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[BargainMonkey]

How does this setup sound:

6P
P91
2xRCR123a 3.7v li-ion

Lumens, runtime?

You'll need to use AW's new IMR cells if you want to do this safely.

 

[^^Nova^^]

If you need a flashlight with this level of output, but would like to be able to run it a little longer without problems, I would personally suggest picking up a FM 2x18650 body, a pair of AW protected 3.7V 18650s, and a LumensFactory EO-9.

The EO-9 on the 18650s is going to be pretty similar to the output of your P91 on CR123s, the size of the flashlight will be 1 cell longer (imagine a "12P"), and the runtime will be close to 1 hour. I would suggest limiting continuous runs to 10-20 minutes depending on ambient temps. The EO-9 will make a little less heat than the P91.

How about running 2 x 17500 in a standard 9P with either the P91 or LF EO-9. I assume the 17500's would be safe with these lamps, with the runtime around the 30 minute mark?

Nova

 

[mdocod]

How about running 2 x 17500 in a standard 9P with either the P91 or LF EO-9. I assume the 17500's would be safe with these lamps, with the runtime around the 30 minute mark?

Nova

EO-9 yes

P91 NO.

Maximum safe discharge rate for LiCo cells is 2C, or for 17500 size cells, about 2 amps. The P91 draws ~2.7A on li-ion cells.

Eric

 

[Bullzeyebill]

How about running 2 x 17500 in a standard 9P with either the P91 or LF EO-9. I assume the 17500's would be safe with these lamps, with the runtime around the 30 minute mark?

Nova

If you can find a really good protected 17500 you will be ok with about 1/2 hour runtime, figuring 7 volts delivered through most of the runtime. See http://www.candlepowerforums.com/vb/showthread.php?t=117117 for some various 17500 cells, and other sizes. Look at 3.5 volts at 3 amps(total 7 volts for two cells) or so and see how that compares mAh wise with different brands and extrapolate 2.5 amps mAh estimate. Of course, unprotected cells are going to show better results, such as MicroFire's in examples.

Bill