Fenix P3D Rebel 100 Heat

I got a pair of P3D Rebels. I noticed that with them on turbo, in less then five minutes they heat up quite significantly. Depending on who you talk to, the head will be too hot to touch, and the body becomes too uncomfortable to handle because of the heat. I compared this to my L2D CE, and it seems that the L2D CE is overall much cooler, and way better to handle, temperature wise. Is this normal?

Does the Standard P3D CE do this?

Also, the P3D Rebel 100, rated at 200 lumens, maybe less, seems no more brighter than my L2D CE. Did I just get a lemon? :sigh::eeksign:

the rebel seems only a tad bit brighter, but it may be due to the reflector
it seems the hot spot is a bit bigger

not sure if this would be 65 lumens worth of difference or not
:thinking::thinking::thinking:

L2D CE left, P3D CE rebel 100 right, around 3 feet from the wall, lights off, 1/30s???

My Fenix P3D Rebel 100lm only reached about 99F in 6 minutes and that was tail standing. Sounds like something is wrong with yours.

Rebel looks quite a bit brighter on the right. Can you take shot under exposed? That would reveal more.

Btw, since the flashlight gets so hot, will it damage the flashlight overtime if I want to put it on my bike and run it for about 1.5 hours at a time? :sigh:

WadeF said:

Rebel looks quite a bit brighter on the right. Can you take shot under exposed? That would reveal more.

Click to expand...

Any idea about overheating and damage to the flashlight?

On a bike forced air cooling will help. Others have tried this with for example the L2D-CE on turbo and found it stays *cold* to the touch.

Grun said:

I got a pair of P3D Rebels. I noticed that with them on turbo, in less then five minutes they heat up quite significantly. Depending on who you talk to, the head will be too hot to touch, and the body becomes too uncomfortable to handle because of the heat. I compared this to my L2D CE, and it seems that the L2D CE is overall much cooler, and way better to handle, temperature wise. Is this normal?

Does the Standard P3D CE do this?

Also, the P3D Rebel 100, rated at 200 lumens, maybe less, seems no more brighter than my L2D CE. Did I just get a lemon? :sigh::eeksign:

Click to expand...

I tested my P1D CE and my P3D R100.
P1D-CE on High (135 lumens?) 139 degrees F at 10 Minutes.
P3D-R100 on Turbo (200 lumens?) 124 degrees F at 10 Minutes
I would guess the the Rebel puts off less heat energy and that gives the longer runtimes.

Turbo is a tradeoff . . .

At high temperatures, the life of the LED and other semiconductors will decrease, but in Turbo mode, the battery life is also a lot less.

Actually, I would be much more concerned about running the lithium batteries that hard.

There have been a number of very serious battery explosions in Fenix lights after running 3 volt Lithiums on Turbo for extended periods (and a few for no reason at all, or after the light was dropped, so I guessing all the vibration on a bike would NOT be good for them).

For daily use involving extended runs in Turbo, I think a NiMH based light would be a much safer choice.

As to your P3D heating up, I think the reason that it seems to heat up more is simply that Fenix is taking advantage of the fact that unlike some other LED's with similar efficiency, the Rebel can handle higher drive levels and still produce useful increases in light output.

Where some earlier LED's tend to 'top-out' the rebel can pump out up to about 200 lumens if you drive it hard enough.

But more drive means more heat, it's that simple.

A perfect LED would run at 683 Lumens/watt and emit only visable light in the useful portion of the spectrum with no IR, UV, or heat as a byproduct.

http://en.wikipedia.org/wiki/Luminous_efficacy

Unfortunately, we are not even close to that figure (and probably never will be).

At just over 100 lumens/watt at high power levels, the vast majority of energy you pump into a LED still turns to heat.

This is physics folks, and the premium LEDs from Lumiled, CREE, and Seoul are neck and neck in the Lumens/Watt race, so you can see it's just a little silly to talk about one brand of LED heating up more than another, because everything that doesn't turn into light WILL turn into heat.

The suggestion to retake the pictures with a much dimmer exposure, is a very good one.

One fellow here made the comment that his P3D 'only' seemed to measure about 1EV brighter on turbo and wasn't brighter in the lower power settings.

The lower power settings are regulated to hold a constant output and aren't really relevant, and the 1EV change in brightness he saw on his light meter in Turbo is DOUBLE the output, indicating the difference between 100 lumens and 200 lumens!

So basically he was complaining that his P3D Rebel light was doing EXACTLY what it was designed to do.

I tested the heat issue in my P3D Rebel by leaving it on my desk in Turbo for about 7 minutes. At the end of that time, it was noticeably warm, but not hot and easily held.

As far as brightness, I posted a review/comparison between the P3DR and the P2D and Surefire G2Z here:

https://www.candlepowerforums.com/threads/171535

The G2Z is rated by Surefire at 120 lumens, the P2d by Fenix at 135 lumens. The P2D put out more than the G2Z, and the P3DR put out more than either of them.

I don't know what 200 lumens looks like, but I think my P3DR100 puts out fairly close to that.

:shrug:

wild68fury said:

P1D-CE on High (135 lumens?) 139 degrees F at 10 Minutes.
P3D-R100 on Turbo (200 lumens?) 124 degrees F at 10 Minutes
I would guess the the Rebel puts off less heat energy and that gives the longer runtimes.

Click to expand...

Probably the main reason for the P3D running cooler after 10 minute is due to its larger mass. A small light like a P1D will heat up faster than a larger light like the P3D.

Luminescent said:

Actually, I would be much more concerned about running the lithium batteries that hard.

There have been a number of very serious battery explosions in Fenix lights after running 3 volt Lithiums on Turbo for extended periods

Click to expand...

Is it a fact that running turbo mode too long causes Kabooms? I think we are lacking information as to which brand of cells the person was using, perhaps they used 1 battery to test a P1 then put that in with a new battery etc.. so many things that can go wrong. Withought the data we cant jump to conclusions.

Does a P3D Rebel, Cree, etc, on Turbo, draw far less power than say a Surefire E2e?

i would think it takes more juice to burn a filiment in gas than it does to power a small circuit . . am i wrong?

The P3D drives the led harder in turbo mode IIRC that's why its rated more light than the P2D. The p2D has the same electronics as the L2D IIRC as well. That tells you one thing right there why it's hotter.

Also the rebel has a wider beam so that may be playing tricks on you, you'd have to do a ceiling bounce test to tell the amount of light is more or less.

WoW, thats running hot

Don't know if it really is that, but I don't have a thermometer, so it is somewhat subjective, though compared to my L2D CE, it is much hotter.

techwg said:

Is it a fact that running turbo mode too long causes Kabooms? I think we are lacking information as to which brand of cells the person was using, perhaps they used 1 battery to test a P1 then put that in with a new battery etc.. so many things that can go wrong. Withought the data we cant jump to conclusions.

Click to expand...

Fact is, YES, turbo mode HAS been directly implicated in several explosions.

Here is one of the best Lithium Battery explosion links:
(you might want to bookmark it)

http://candlepowerforums.com/vb/showthread.php?t=124776

This guy was able to make Lithium batteries explode at will over and over again (even supposedly high quality 'name brand' batteries).

It seems like every time there is a Lithium battery explosion (and there have been MANY), people start speculating about how this guy must have messed up some how, or just had a bad battery, etc.

They desperately need to convince themselves that there was SOMETHING that was wrong, so they can believe that it just CAN'T happen to them.

Sorry, folks, this can happen to ANYONE, ANYTIME, who uses Lithium batteries in high drain flashlight applications.

The Fenix lights are ideally suited to causing lithium battery explosions (very high current draw, coupled with high operating temperatures).

So, anyone for a nice game of Fenix-Roulette?

Think of spinning the bezel of your Fenix around to the 'Turbo' setting like spinning chamber of a gun during a game of Russian-Roulette.

Click,

Click,

Click,

BANG!!!!

Conclusion:

Lithium batteries in flashlight applications are *VERY* dangerous.

Yes, they do blow up.

All brands of Lithium batteries can explode.

Each individual lithium cell seems to have a different random threshold, and you never know what it is, but if you accidentally push beyond that point even a little bit - BANG!!!

Think this will NEVER happen to you? I suppose that's what these folks thought:

https://www.candlepowerforums.com/threads/169038

https://www.candlepowerforums.com/threads/120888

https://www.candlepowerforums.com/threads/122500


These were just a few links. I could list LOTS of others.

Bottom line:

It CAN happen to you.

I personally would not have one of these 'pocket incendiary devices' if you gave it to me, but if you do own a lithium cell light, you will want to be very, very, very, careful with Lithium batteries.

I read that article and there was no mention of Fenix, or using TURBO. Are you trying to saying using TURBO on a Fenix light, like a P3D, draws more juice than a Surefire E2e??? A Fenix P3D will run for 1.8 hours or longer on two CR123a's while the Surefire E2e is rated for 1 hour. That should mean the Surefire is draining the batteries twice as fast, and I don't hear about E2e's blowing up.

I think it's kind of funny to think of a LED light as high drain flashlight compared to incans.

WadeF said:

I read that article and there was no mention of Fenix, or using TURBO. Are you trying to saying using TURBO on a Fenix light, like a P3D, draws more juice than a Surefire E2e??? A Fenix P3D will run for 1.8 hours or longer on two CR123a's while the Surefire E2e is rated for 1 hour. That should mean the Surefire is draining the batteries twice as fast, and I don't hear about E2e's blowing up.

I think it's kind of funny to think of a LED light as high drain flashlight compared to incans.

Click to expand...

The first link I posted in the second group involves a battery explosion (a rather nasty one) in a Fenix P1D LED light.

The second link involved a Pelican Incandescent. I believe Pelican is the company that brags about safety features like 'hydrogen absorbing pellets' on their web page, but apparently it didn't help in this case, because this explosion was so nasty that the owner was left bleeding from shrapnel injuries.

Both lights have characteristics that lead to issues with Lithium batteries.

As you pointed out Incandescent lights draw more current (and lithium batteries don't like that).

LED lights, on the other hand, heat up more (and Lithium batteries don't like that either).

You may find it surprising that LED lights with their lower current loads would actually heat up MORE, but it turns out that an Incandescent bulb is actually 100% efficient at turning electricity into SOMETHING, it's just that most of that 'something' is not very useful Infrared energy. Most of the waste IR is radiated right out through the lens however, so the light doesn't heat up much.

Even the best LED lights are less than 25% efficient, and unlike incandescent lights the all of the waste energy gets coupled into the body of the flashlight.

I am a bit concerned about the Rebel version of this light specifically because Fenix is driving the Rebel really hard in an attempt to get 200 lumens in Turbo mode.

With Two 3 volt Lithium batteries the P3D should not get into too much trouble on current draw, but if it's driving the Rebel that hard and the light heats up enough, then that could be a problem.

This is no doubt why Fenix recommends to limit the runtime in Turbo mode.

In some cases the Lithium batteries seem to blow for no reason whatsoever. This is why I plan to stick with NiMH in my lights for now.