Single CR123/RCR123 lights getting very hot.

First off - hi all. First post. Been lurking here about a month since picking a few energizer LED flashlights up at Target and thinking there's gotta be something better out there. Google searching led me here and I can blame all of you for my now dwindling savings account. :mecry: :laughing:

Seriously though - I have had a flashlight addiction for a long time. Just didn't know there was so much good stuff out there.

So now that I have bought at least one light that takes one or more of the following batteriesL CR2, CR123, AA/14500, AAA/10440 (LD01 rocks on li ion for show), 17670, 18650, etc, etc, etc........ I have to say that I may like one of the cheapest lights - the MG L-Mini II the best - tremendous light for $40.

My real question is in regrads to the single CR123 and some single AA lights and the heat they generate. I've timed runs on high for the NiteCore D10 on NiMH and LiIon, the EZ123, The Quark 123, the PD20 and after about 10-15 minutes they all get REALLY HOT. Like almost too hot to touch. I measured the heat on the side of the D10 and EZ123 and Quark 123 near the head and it was between 140-150* F. The Quark was a little better. And these readings are on primaries, not elevated coltage runs.

Am I doing something wrong? I would be afraid to run the D10 for 1 hour even to test the runtime of the light. I am wondering how all the reviews on the site here are capable of running their lights on high long enough to complete their testing.

ShineOnYouCrazyDiamond said:

Am I doing something wrong? I would be afraid to run the D10 for 1 hour even to test the runtime of the light. I am wondering how all the reviews on the site here are capable of running their lights on high long enough to complete their testing.

Click to expand...

:welcome:

You are not holding the light in you hand or cooling it in some other way.
For runtime testing many people uses a small fan to cool the light.

HKJ said:

:welcome:

You are not holding the light in you hand or cooling it in some other way.
For runtime testing many people uses a small fan to cool the light.

Click to expand...

Thx - I had a feeling the answer was that obvious. I guess the bigger lights just disapate the heat better.

ShineOnYouCrazyDiamond said:

Thx - I had a feeling the answer was that obvious. I guess the bigger lights just disapate the heat better.

Click to expand...

Small flashlights (and larger lights to some degree) do not have much mass to use as a heat sink to remove heat via passive cooling eg air currents

So they rely on you & your body to act as a heat sink via active cooling eg heat is absorbed by your body & transported away from the site via your blood.

Yes, hand heat sinking is one of the easiest ways to remove heat from the flashlight. However, the primary reason is too much current to the LED in the small format flashlights. We want the brightest, highest lumen rated little light, and we pay for it in increased heat and reduced runtimes. Running these little lights at 350mA's max to the LED would help solve the problem. Endeavor does it with his CR2, and CR123 lights, and it works and the runtimes are 1 1/2 hours on high with his little CR2 lights, and little heat is generated. Some of the larger CR123's lights, like the Quark can handle a little more current to the LED, and they should at least get 1 1/2 hours on high. Some of the little dinky AAA lights using power LEDs have a hard time holding the heat down even at 350mA's to the LED.

Bill

A few questions

This night I made a runtime test of my Maglite C customed for 1xCR123 with a Malkoff XP-G dropin. This dropin puts out around 200lumens initial brightness which quite fast drops. Actually it acts like direct drive though the dropin has a regulated driver. The light tailstanded on the table.

*Is the reason that one CR123 isn't really adequate for the current drain of this dropin? I think the heatsinking would be good enough?

*After 45 minutes (the brightness was then halved) I felt that the body was warm and I switched off the light. The Surefire battery felt very warm but not really hot. Is this a risk with a CR123, or is it ok as long it's not burning hot?

Thanks in advance, Patric