Am I crazy! I put L1 head on E1e body direct drive w/ 3.6v 900mah RCR123... Pic!

My black E1e body came today and I was in the mood to "fiddle" So I got my L1 head out that I had and adjusted the wires to make the correct contact and it lights! Talk about a short, squat light! And on a BatteryStation 3.6V 900mah RCR123! Is that too much for it! Should I use a primary with a direct drive like that? Any guess as to the runtime I'd get like this? Anyway, heres a quick webcam pic.

I just tried it off a primary and it seemed dim. Am I correct that the RCR123 is OK, even fresh of the charger at 4.2v?

Another funny thing is, I had a black KL1 head & Z61 on order from OpticsHQ, but they were out of stock of the black KL1s' so I cancelled the order, kinda perfect timing seeing as how this works?

No one knows if its safe to run it like this?

You might be overdriving it a bit. I've seen low Vf luxeons pull over an amp and a half from an 18650 li-ion cell. Of course, R123A cells aren't nearly as meaty, and they tend to sag a bit under that kind of load.

Oof. It DOES seem kinda bright. You think it would burn up if I left it on a long time? The emitter thats' in there is a UW0K...

KDOG3 said:

No one knows if its safe to run it like this?

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Hello KDOG3

Since the vf is unknown, it's not definately to say. To go sure, you can try to add an 0.2 watts, 1 ohms resistor.( If it's a newer head with a LuxIII). If the brightness will be ok, you're on the safe way for longer runtimes.

Best regards

____
Tom

Oh, you add the bin-code...an UW0K seems to be perfect to DD by one RCR.

So you'll need no resistor IMO.

Best regards

____
Tom

Why not measure the current at the tailcap? Above 750mA is bad

I have no way of measuring the current. If the emitter will be damaged by this battery, I may have to go with a K2 emitter - I hear they can take more current than the LuxIIIs'.

You would need around a 2 Watt resistor to be safe. At least a 1W, but that will still get hot. You are running a lot of current direct drive off an RCR.
I currently have some flashlight dual stage switches that use resistors, and the resistor gets very very hot if you don't have enough wattage, especially with low ohm resistors.

Long John said:

Since the vf is unknown, it's not definately to say. To go sure, you can try to add an 0.2 watts, 1 ohms resistor.( If it's a newer head with a LuxIII). If the brightness will be ok, you're on the safe way for longer runtimes.

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I run a TY0K direct drive with a 18650 (in a cheap military anglehead), and it's only pulling 400-450ma from the battery. There might be a fair bit of resistance from the cheap materials used in the light, but it seems pretty safe to me. Your mileage may vary...

With that amperage, you might be OK, but I think KDOG's setup is direct drive using high quality Surefire components and an unknown LED. I have a light with a 2W 2ohm resistor that burned it's resistor solder off, and in my calculations and testing with 10, 15, and 20 ohm resistors, and RCR2's, I was getting up to 1.2 amps DD, and the resistors needed 1/2 W at 10 ohm, and still over 1/4 W at 20 ohm. At lower ohms, you need a lot more wattage capacity. In my 1.2 amp light test I think I remember needing over 1W for 5 ohm. I'd give more specific info, but I don't have access to my notes right now. Some others have done testing...

I did some searching: Look at post #24 on this thread. Also post number 22 has good info specific to the P1, but probably close to what you would see in the KDOG mutt. jugeh did some testing that helped me get going in the right direction and that I later duplicated in my testing. His charts are way better tham my data though.

Remember to err on the high side here for safety and reliability sake. To be accurate, you need to measure the amp flow through the resistor and gauge the wattage accordingly. jugeh's graph in post #24 of that thread is only a specific example. Look for some of the on-line resistance calculators, they will calculate the minimum wattage resistor you need.

LEDcandle said:

I run a TY0K direct drive with a 18650 (in a cheap military anglehead), and it's only pulling 400-450ma from the battery. There might be a fair bit of resistance from the cheap materials used in the light, but it seems pretty safe to me. Your mileage may vary...

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The emitter in this set up is a UW0K. I used it at work today and it seemed to run fine. However I have considered getting lower current RCR123s for this setup such as the BatteryStation 750mah ones.

KDOG3 said:

However I have considered getting lower current RCR123s for this setup such as the BatteryStation 750mah ones.

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The rating on the cell is an indication of its capacity, not the instantaneous current it can provide. Your 900mah cell isn't necessarily going to push 900ma through your emitter. Rather, it is rated to provide 900ma (into a load with sufficiently low forward voltage) for a duration of one hour.

Of course, cell capacity ratings are generally overstated. I wouldn't be surprised if most "900" mah cells are actually closer to two-thirds that.

So do you think I'm ok with this setup?

K bin will have the best chance of surviving of any Lux3.

KDOG3 said:

So do you think I'm ok with this setup?

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Ok, so can you recommend a good bin? I didn't even know they made K-bins, unless you mean like a UW0K, UV1K, etc.

KDOG3 said:

Ok, so can you recommend a good bin? I didn't even know they made K-bins, unless you mean like a UW0K, UV1K, etc.

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Yeah, that's what I mean, the other bin code digits don't have an effect on whether it will work with any specific voltage/current. The first three digits just affect how bright and what tint it is. Sorry about that - not being so clear, once you get used to what code means what, you kind of assume others do too. I should have said Vf bin of K (or better (higher) but I don't know if any higher Lux3 Vf bin exists).

Ok, no problem. So the higher the bin, the more voltage/current it can take? I really wish they would come out with some higher ones, I could *swear* I saw a UV1L some time ago, I could be wrong however.