RCR123 in Surefire L1 Cree...IT WORKS!! And brighter to boot!! + E1L on RCR123

Hey everyone,

Well I received my new Cree Surefire L1 and E1L from OpticsHQ (excellent service!!) and of course was curious to see if I could get some guilt-free lumens by using rechargeables.

One of the newer AW RCR123 cells easily fits inside the Cree E1L body, but some weird things happen with the output. Put short, it is slightly brighter, but every second, it will flicker back to it's normal output level and then return to the brighter state. Weird...

Tonight, I was bored so I tried to fit a RCR123 inside my L1. It didn't quite fit, but it also wasn't impossible to wedge it in. The silver label was bunching up when I tried to slide it in the body, so I took it off and it helped a bit. It is a pretty tight fit, taking a couple of firm shakes to get the battery to slide out, but not so tight that it is nearly impossible to get the battery out. I put on my :tinfoil: and switched her on...whoo hoo no flicking :twothumbs

I will say that the light is VISIBLY brighter than before. Both the low and high levels are brighter to the naked eye. I am very happy with this because while the stock output is phenomenal, I am used to slightly brighter lights that have a bit more throw. My old EDC is a Ti McGizmo S27 PD that I bumped up the drive current from 525mA to 833mA. The light now comfortably reaches out and touches things that it very faintly lit before. I'm loving the beam too because whereas the S27 can reach out a bit further, the area lit downrange is smaller. The L1 puts out a nice large round circle of light that is about 2x the size of the S27 hotspot at 30 ft.

Here are some measurements on what the light is pulling from the battery. Unfortunately, I can't measure how much the light pulls on low as I understand that the tailcap controls this...

With a fresh Surefire CR123 cell, the light pulls 630mA on high. With a RCR123, the light pulls 830mA on high.

I also took some lux@1 meter readings.
On CR123,
480 on low
3000 on high

On RCR123,
830 on low
4400 on high

I left the light on high for about a minute in front of the meter and the lux reading didn't change so it has no problem regulating at this voltage.

Of course, the light gets up to temperature quicker, but I don't think it will be a problem as it seems to have very good heatsinking.


Needless to say, I'm one happy camper :naughty:

I briefly tried an RCR in the L1, and it did seem brighter. I was nervous to try it for very long, and the UF 123 almost got stuck so I haven't tried it since.

I'll probably try it again with some AW's based on your results, thanks.

You have proven that the L1 Cree uses a boost circuit. The RCR123 is overdriving the circuit/led and you are running in direct drive, no regulation. If the circuit was a buck/boost, or buck, the current from the battery, using the RCR123, would have dropped, not almost doubled. You will have problems down the road.

Bill

I ran my L1 with LIFePO4 RCR123 and it ran for 25min at Max Lumen. Measured voltage of the battery immediately was 2.2V. For those that may not know, the LIFePO4 battery are 3.2V freshly charged. You will need a special charger for it. I don't mind swapping battery and this is what I used with my L1, Gladius, and A2.

Any update on the status of your L1 w/ RCR's? I've been wondering about sticking one of my AW RCR123's in my L1... but the voices in my head tell me not to!

I've been using it for about 2 weeks now with only 3.7v RCR123...so far no problems. I believe Bill may be correct in that it is going into some form of DD...but it is strange. I've never head a DD light that pulls current from a battery in such a steady fashion. With my other DD lights, the current measured from the battery will jump around a lot(within a 10mA range); with this light, the current pull stays rock steady. weird.

I've also found that if I can press the switch with just the right amount of pressure, I can get 3 distinct outputs. It looks like low, high w/ cr123, high w/ rcr123.

The increase in brightness is definitely worth it for me...try at your own risk...but I'm sure you'll get hooked

cryhavok said:

I've been using it for about 2 weeks now with only 3.7v RCR123...so far no problems. I believe Bill may be correct in that it is going into some form of DD...but it is strange. I've never head a DD light that pulls current from a battery in such a steady fashion. With my other DD lights, the current measured from the battery will jump around a lot(within a 10mA range); with this light, the current pull stays rock steady. weird.

I've also found that if I can press the switch with just the right amount of pressure, I can get 3 distinct outputs. It looks like low, high w/ cr123, high w/ rcr123.

The increase in brightness is definitely worth it for me...try at your own risk...but I'm sure you'll get hooked

Click to expand...

I really want to try it... but the thought of putting 2xRCR123's in an L4 and blowing it is always in the back of my mind after reading countless threads about it. If the L4 and the L1 are both boost, and putting 2xRCR123's in the L4 will kill it... it makes think that putting a RCR123 in the L1 will damage it as well. But maybe the L1 can handle it? I have tried slipping some AW cells in the body and it fits... it's just a bit tight. Taking the silver label off does help as well, but I haven't mustered up the courage to actually press the switch yet! :mecry:

EDIT: Now that I think about it... people use RCR123's in their Fenix P2D-CE's which is a similar (same?) cree and they seem to work out ok. Would it be safe to assume the L1 would get a similar run-time plot as seen on this thread's graph of the P2D using an AW RCR? (in purple): http://candlepowerforums.com/vb/showthread.php?t=163405

What are you current readings at the tailcap at start up and after 10 minutes or so. Compare them to the current with one CR123 and post please. Thanks,

Bill

Here's a quick chart I threw together.



Couple of things to add:
Starting voltage of the AW RCR123 was 4.03V, so it was about 1/2 fully charged. Starting voltage of the SF CR123 was 3.08V

The initial reading of 840mA for the L1 on RCR123 only lasted about 10 seconds...during which it dropped and settled in at 810mA.

Voltage measured right after the test of the RCR123 was 3.84V. The CR123 was 2.86V

The light got hotter when it was using the RCR123 when compared to the CR123, but not too hot to handle.

After I completed the tests, I went to my light meter to see if any change in brightness had occurred. The light still puts out the same lux@1 meter numbers as usual with both batteries.

I tried to do the same test with my fully direct drive KL1 running a Seoul P4 off of an AW RCR123. The readings jump and fall continually over a range of about 80mA, so it was impossible to plot anything worthwhile. It does not hold a relatively constant current reading like the L1.

cryhavok said:

Here's a quick chart I threw together.

Couple of things to add:
Starting voltage of the AW RCR123 was 4.03V, so it was about 1/2 fully charged. Starting voltage of the SF CR123 was 3.08V

The initial reading of 840mA for the L1 on RCR123 only lasted about 10 seconds...during which it dropped and settled in at 810mA.

Voltage measured right after the test of the RCR123 was 3.84V. The CR123 was 2.86V

The light got hotter when it was using the RCR123 when compared to the CR123, but not too hot to handle.

After I completed the tests, I went to my light meter to see if any change in brightness had occurred. The light still puts out the same lux@1 meter numbers as usual with both batteries.

I tried to do the same test with my fully direct drive KL1 running a Seoul P4 off of an AW RCR123. The readings jump and fall continually over a range of about 80mA, so it was impossible to plot anything worthwhile. It does not hold a relatively constant current reading like the L1.

Click to expand...

Wow thanks for this! Do you think it would start much higher and drop quicker to that level if the AW cell were fully charged?

cryhavok said:

One of the newer AW RCR123 cells easily fits inside the Cree E1L body, but some weird things happen with the output. Put short, it is slightly brighter, but every second, it will flicker back to it's normal output level and then return to the brighter state. Weird...

Click to expand...

I'm confused. You say the L1 works just fine with R123's, but you point out this "flicker back to its normal output". Either I'm not understanding things right, or something's not right with this setup.

greenLED said:

I'm confused. You say the L1 works just fine with R123's, but you point out this "flicker back to its normal output". Either I'm not understanding things right, or something's not right with this setup.

Click to expand...

It works in the L1 but the flickering takes place in the E1L-Cree...

Many thanks, jcompton. Coffee's not hit brain yet.

Interesting. I wonder if the results would be similiar with a fully charged LiIon? Please do more testing, this is very strange. That flat current draw. Do you have a lightmeter? Would be nice to see a runtime with lightmeter.

We now know that the L1Cree can handle 4.3 volts safely, and that is good.

Bill

Bullzeyebill said:

We now know that the L1Cree can handle 4.3 volts safely, and that is good.

Click to expand...

4V are definately above the Vf of the led, meaning it runs in direct drive. That is well out of spec. Considering the L1 is a light that has a planed service life of several years, it is questionable if one can really say it can handle 4V.

It is out of spec and I usually argue against overdriving a boost circuit. But what we have her is a apparent modest boost in voltage/current to the led at least at a starting voltage of 4.03. It could indicate that the this particular Cree led has a fairly high vf. The real test would be this L1 Cree driven by a fully charged RCR123, at least for a short time to see what the current is. If it jumps well over 1 amp and stays there then forget it. The RCR123 is a different animal compared to a higher capacity LiIon. It's voltage will drop off fairly fast under a load of 1 amp or more. The exception would be an unprotected RCR123 such as a Powerizer 3.6-4.2 volt battery.

Bill

I use the green label 3.0 V 17335 cells from Lighthound. They work very well in my L1 lights with no ill effects at all that I can tell. Works just like a primary, haven't done a runtime test. Fits all the L1 bodies, square, round and the new style too. No scraping or removing labels either.

Well I decided to go for it. Stuck my 90%ish AW RCR123 (the only one I had that would fit, took the silver label off, need to slap it to get the cell out but it's not too bad) and tested it out. The low beam is definitely brighter, and the high is higher as well. Left the light on high for about 10 minutes, it seems pretty stable, but it gets warmer faster than the primary. After about 5 mins it reaches a stable temperature which is a tad warmer than leaving the light on high with a primary but it's no where near uncomfortable like an L4 would get. It's still not as warm as my incan E2D gets.

Well so far I like it! I just have to hope it's not killing the LED... but time will tell.

I would imagine if the output is bluish then the led is seriously overdriven, if it is brighter but with the same tint then it should be ok.....My experience is from direct driving an L1 head (Lux TIR) on a E1L body fed with AW's R123a (Direct Drive). Awesome output, but somewhat bluish tint, no magic smoke though....

Very interesting. I have 2 BatteryStation 900mah 3.7v RCRs' sitting here that I don't know what to do with. If they will work in my new L1, that might be an option. Hmmmm....