Question ---- E1E with 5 Watt KL4 Luxeon Head

Can anyone tell me how much runtime I can get from a single battery in an E1E (continuous use) with a KL4 5 watt head?
I realize that SureFire doesn't recommed using this head on this light body but I have read that it works GREAT. I just wonder how long a battery will last.

LOOOONG. There was this comparison with a modded Arc LS, a baby pin and a few others. It's dims VERY slowly. (You could always toss a rechagable 123 into there)(4.2V)

ConstableScott

Of the four KL4 heads I tried, I averaged about 35-45 minutes of impressive brighter-than-KL1 light before it dimmed to the comparable KL1 light level. I understand that some of the KL4 heads will not work, or, are very dim when turned on. I guess that I have been lucky in purchasing KL4 heads with a Vf below 3 volts. How long they will run after passing below the KL1 output level of 15 +/- lumens is unknown to me since I have never run them until the batteries were dead. If anybody could tell us we would all be greatful.

Hope this helps.

About half an hour sounds about right for a KL4 on a single cell body. Your actual runtime will depend on the Vf of you particular luxeon V.

The single cell configuration doesn't work on some KL4 because the Vf is too high. The lowest Vf 5W starts at something like just over 6 volts.

Keep in mind that even with a low Vf luxeon in your KL4, you won't be getting full regulation. It'll run at about half the current on a single cell, if it runs at all.

Why don't you just go over to JSBurley's and get a set of rechargeable 123's. They ring in at 4.2v off of the charger. That way you wouldn't have to worry about the runtime. Just don't stick two of these into an L4 body. You might fry the lux and/or the circuit.

I'm getting a runtime of about 25 minutes when running KL4 with a single rechargable 123 cell.