JIL CR2 DD battery

I've had my JIL CR2 DD for a while now, and have fairly recently been using it on CR2 rechargeables (350mAh, if I remember). As there is no up/down converter in the DD, it's running straight from the cell, but nothing 'bad' has happened yet, although the light gets ferociously hot, if left on while the beam is full brightness, before it dims noticeably.

Am I likely to damage the LED doing this? I'm getting about half an hour of full brightness before it dims rapidly, and I'm charging the cells using a Nano charger. As a long runner on CR2 primaries, it's good, but the light from it on rechargeables is awesome, like an ORB RAW on high.

I use RCR2s in my JIL DD too. Given the light's brightness, I'm pretty sure the LED (TWOJ LUX III in my case) is being over driven. I would be more concerned if I had an H rather than a J series LUX; but, replacing a LUX III LED is no big deal if required and now much less expensive given the drop in LUX III pricing. I also really like the JIL DD's extreme brightness on a lithium ion battery.

A RCR2 Li-ion should only be used in the TWOJ version. A J Vf bin should handle up to 3.51V, and a 3.7V Li-ion should be OK, but remember that hot off the charger, a Li-ion can start at 4.2V. You get a lot of WOW up front before it dies off to what is probably close to what you should expect from the DD. I run an RCR2 on my Intelli (TWOH) and on level 20 (burst) it gets hot very quickly. I won't use it for more than a few seconds at that level.

IMO the only real reason for running a TWOJ DD with the RCR2 is for brief WOW blasts. The true advantage of a Jil DD is realized with a lithium CR2 (TWOH) that lasts 20+ hours. If yours is a TWOJ, it'll still run off of a CR2, but you'll get "the plunge" earlier.

I still have my JIL CR2 DD, (serial #65), from the original run and I love it. I tried it on RCR2's when I first received it and even though it was bright, it wasn't enough difference to me to not just use primary CR2's. You're overdriving the emitter enough with 3.7V RCR2's and it generates enough heat that it will go south long before it would using primaries. Besides, who wants that heat and short runtime for such a great light.

Maybe I won a luxeon lottery with mine but my JIL DD using primaries has a flawless, bright, white beam and it's still bright enough for almost any use using primaries. It also NEVER gets hot even if using it where it may have to be on for hours and 20 hours+ of diminishing runtime is fabulous.

I think that the JIL DD is the KING of the whole crop of miniature CR2 lights out there and especially at it's price point. As a plus, of all the miniature CR2 lights I have, only the TnC lights can compete with it as far as build quality goes.

My Jill DD kicks some serious butt when using RCR2 cells. There's a huge visible difference between using the rechargables vs the lithiums. I exclusively run RCR2's in my Jil. If/When the emitter dies, I'll just throw in a new module.

Gene said:

I think that the JIL DD is the KING of the whole crop of miniature CR2 lights out there and especially at it's price point. As a plus, of all the miniature CR2 lights I have, only the TnC lights can compete with it as far as build quality goes.

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Is it better than an Ion or even a HDS Ultimate ?

Perfectionist said:

Is it better than an Ion or even a HDS Ultimate ?

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I'm pretty sure the JIL-CR2 Intelli (or JIL-CR2 DD with an appropriate bin LED) using a RCR2 Li-Ion cell is brighter than an Ion, althought I don't have one to do a comparison. I've read the Ion produces a rather floody beam, while the new JIL JCR2 models have a McR-18 reflector which gives a good hotspot. The JIL should even be brighter than the HDS, since HDS doesn't overdrive their LED's. If you put a U-bin Lux-III in the JIL DD or Intelli it will certainly match or outperform anything with a similar size reflector.

Wow !!

I wish JIL would hurry the funk up and release their Chrome version !!

Is there anybody who might mod the JIL for me with a U-bin ??

Perfectionist said:

Wow !!

I wish JIL would hurry the funk up and release their Chrome version !!

Is there anybody who might mod the JIL for me with a U-bin ??

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Goldserve makes U-bin FLuPIC sandwiches for the JIL: https://www.candlepowerforums.com/threads/119470

Other than that, try the 'modding services' thread that greenLED maintains: https://www.candlepowerforums.com/threads/100070

I'm going to be trying to figure out how to mod my own JIL's to upgrade the LED's. It is supposed to be fairly easy (as mods go).

Does the RCR2 give the DD JiL more power than a RCR123 driving a Fenix P-1?

tsask said:

Does the RCR2 give the DD JiL more power than a RCR123 driving a Fenix P-1?

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I don't have a Fenix P1 to compare, but it doesn't really matter because the RCR2 in a JIL Intelli (or JIL DD) drives the Luxeon-III with as much current as the LED can handle. The Fenix P1 can't possibly drive a Luxeon-III harder (without burning out the LED or making the light too hot to hold).

In the JIL DD, a xxxK bin LED is recommended if you plan on using a RCR2 Li-Ion cell. The xxxJ bin LED's don't like being overdriven that much for long, though some people do it.


For reference, I measured the current in my JCR2-LR (with TW0J Luxeon-III) with a Li-Ion cell:
14500 Li-Ion at 4.0V --> 1.35 Amps at start, dropping to 1.30 Amps after about 15 seconds as it heats up (I didn't run it for long). That's well over 3 watts.