Jetbeam MK1 gets REALLY hot with a RCR123

9volt

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So I guess I got lucky - 1 of the 3 AW RCR123s I got from Lighthound today fits in my Jetbeam w/o any modification. I've been playing with it tonight and the suckers gets HOT and it gets hot FAST. Within a couple minutes of use it's almost too hot to touch to turn it off. Is this normal for this light?

I hope it's normal because it's seriously bright on the rechargleable :)
 

LEDcandle

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Yup it is. The heat buildup starts from the get-go. Diff measurements I've come across, including my own, indicate that about 1.4 - 2+ A current is involved. Some of them even had their LEDs die in 10 secs (I guess those were the ones in excess of 2A)

If you hold the Jetbeam in your hands, it'll help conduct the heat and it shouldn't build up to an unbearable heat. If you leave it on a table or something, you'd better be careful about touching it after a couple of minutes.
 

9volt

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To clarify, is it ok to run it on an RCR123 even though it gets so hot?
 

havand

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dammitjim said:
To clarify, is it ok to run it on an RCR123 even though it gets so hot?

Technically, yes. However, I won't run mine on without being held for more than a minute or two.
 

9volt

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I was hoping to use the tripod mount threads on the bottom of the 123 tube to fashion a bike mount for this thing. Am I likely to burn out the light running it this way on a rechargeable? Is there any good way to deal with the heat or a battery alternative that doesn't generate so much heat?
 

Paul6ppca

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You could try the new Life po4 rcr battery ,its 3.2 v,so it shouldnt get as hot or as bright.Check the dealer section for more info on runtime IIRC it a 500mah.

https://www.candlepowerforums.com/threads/125353

These are new generation R123 with safe chemistry that will not vent with flames ( explode ). The key to this safety feature is that no oxygen will be released from the oxide structure of the cell composition even under abused conditions. No oxygen means no pressure built up and fuel for combustion. Can be used in series on multi-cell appliactions.

Specifications :

Nominal Voltage : 3.2V
Capacity : 500mAH
Lowest Discharge Voltage : 2.0V
Standard Charge : CC 250mA CV 3.6V
Cycle Life : > 500 cycles
Weight : 16.5g
 

Nell

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dammitjim said:
I was hoping to use the tripod mount threads on the bottom of the 123 tube to fashion a bike mount for this thing. Am I likely to burn out the light running it this way on a rechargeable? Is there any good way to deal with the heat or a battery alternative that doesn't generate so much heat?


The Jetbeam is designed to handle the voltage if I remember reading correctly. The bike mounting can help disipate heat if you can secure it to something metal acting as additional heat sink. The air movement arond the lamp should also help quite a bit.
 

lrp

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I have the MK 11 and run it with a protected 14500 and it really get hot and there is no problem. It really puts out the light on that cell!!
 

Tremendo

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My 1st version JetBeam CR123 only fits with the 900mAh RCR123 I got from Lighthound. Otherwise it's primary CR123's. It does get very hot with the RCR123, so much that I normally use it with CR123's. Also for longer shelf life, since it's not an EDC.
 

TooManyGizmos

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dammitjim said:
I was hoping to use the tripod mount threads on the bottom of the 123 tube to fashion a bike mount for this thing. Am I likely to burn out the light running it this way on a rechargeable? Is there any good way to deal with the heat or a battery alternative that doesn't generate so much heat?

:grin2:.... Vibration & Jolts ....... + heat ..... may be too much for it.

I suggest you try Tenergy 3.0v Pro-tected Rechargeables in it .

Then I don't think it would get so hot ..... But should be just as bright . They are small enough in diameter to fit in most lights - I think ?

.
 

9volt

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TooManyGizmos said:
I suggest you try Tenergy 3.0v Pro-tected Rechargeables in it .

.

Where can I buy these?

Thanks for all the help!
 

Kippers

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Jim,
I got the 3.0V 900mah Tenergy RCR123a from BatteryJunction.com. You must buy a different charger from the ones used to charge Li-Ion 3.7V to charge these cells. Battery Junction sells 4 batteries and charger combo for a good price. Look under Battery & Charger Combo on the left of their web page. I have this setup and it has worked well so far. Batteries don't heat up much when charging so no need for fan.
Kippers :candle:
 

TooManyGizmos

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:):grin2::naughty:..... I agree with what Kippers said .

And I also got my charger & batt's from BatteryJunction .
Make sure you get the 900 Mah ones - not the 750's .

And yes / the 3v Tenergy's must be only charged on their own special charger .

Kippers said:
Jim,
I got the 3.0V 900mah Tenergy RCR123a from BatteryJunction.com. You must buy a different charger from the ones used to charge Li-Ion 3.7V to charge these cells. Battery Junction sells 4 batteries and charger combo for a good price. Look under Battery & Charger Combo on the left of their web page. I have this setup and it has worked well so far. Batteries don't heat up much when charging so no need for fan.
Kippers :candle:
 

jsr

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My Jet1 MK1 gets too hot to hold even while holding, but that's when I've got it on for 20+ minutes. If you leave it alone, as already said, it gets too hot to touch.
The 3V rechargables will run similar to a primary, so a bit less output but also less heat and longer runtime. Still blazing bright on a primary or 3V rechargable. A good option if you haven't already inundated yourself with 3.7V rechargables.
 

Tremendo

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Has anyone burned out their LED on the MK1 JetI CR123 using a RCR123? It does get hot, I don't mind it, but I also like to use it as a bike light for my son's bike (30+ minutes on, no touching). I have been using CR123 in that case, since it's not being held. If the heat doesn't seem to damage this light, that's be good to know that RCR123 is an option for me.
 

jsr

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My Jet1 MK1 had a problem and I got a new head. The LED didn't go out, but the output got really dim. At the time, I was using it as a bike light with the light held between my finders while my hand was on the handle bar. It didn't get hot because the night was cool and plenty of cool air running over the light. I didn't run it for that long...maybe 20min...and it got dim. I was running it off a 14500 battery tho, which draws more current than a 16340 (R123A). Off a 14500, most MK1s draw about 1.7-1.85A (my old head drew 1.84A, my new head draws 1.74A). Off a R123A, it draws about 1.4A.
 
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