I hope this isn't a stupid question or one that has been addressed in another thread, but I just noticed something on SureFire's site that seems very odd. I was looking at this comparison chart http://www.surefire.com/maxexp/main/co_disp/displ/pgrfnbr/528/sesent/00 and noticed that the runtime of the 6PL with the P60L lamp is listed as 11 hours while the runtime of the G3Z with the same lamp is listed as 9.42 hours. The output of both lights is the same, 80 lumens. I don't save much technical savvy yet with lights, but I'm trying to learn. I would have thought (ie, ASSumed) that the G3Z which has 3 CR123's would have provided a longer runtime than the 6PL which uses 2 CR123's if both lights had the same output. Would someone explain this difference in runtimes, please? Thanks for helping to educate a newb! :twothumbs
Runtime of SF 6PL vs G3L
- Thread starter rumack
- Start date
Help Support Candle Power Flashlight Forum
Welcome to the FALSE/MISLEADING "run-times" by SF show!
I have many SF lights (and I like MOST of them, with the exception of the new TIR ,"no spill", needle beam lights of the "new" E/L series), but I am very displeased with their new FALSE/MISLEADING "run-times" ads.
They (SF) have desided to take the "low road" of using FALSE/MISLEADING (at best, where I come from they call it a lie) "run-times" to sell lights.
I hope to "see" SF "step up and do the right thing" and use ACTUAL/TRUE "run-time" quotes (to 50%). 8 hrs. (of 12 hrs.) of less then 5 lms. (or so) of light, from a 80 lm. light, does not "cut it" from a company that was/is "one of the best".
My .02 FWIW YMMV
I have many SF lights (and I like MOST of them, with the exception of the new TIR ,"no spill", needle beam lights of the "new" E/L series), but I am very displeased with their new FALSE/MISLEADING "run-times" ads.
They (SF) have desided to take the "low road" of using FALSE/MISLEADING (at best, where I come from they call it a lie) "run-times" to sell lights.
I hope to "see" SF "step up and do the right thing" and use ACTUAL/TRUE "run-time" quotes (to 50%). 8 hrs. (of 12 hrs.) of less then 5 lms. (or so) of light, from a 80 lm. light, does not "cut it" from a company that was/is "one of the best".
My .02 FWIW YMMV
270winchester
Flashlight Enthusiast
lots of shouting here.
Surefire does define its runtime as "useful" runtime, running until there is enough light to find a key hole in the dark. By comparison many import lights have the run-until-light-suddenly-shuts-off runtime. Not good for people who don';t want to be left in the dark.
BTW the newer TIR lights have enough spill to be useful, not sure where the "needle beam" came from. In fact beyond 5-10 yards the TIR SFs have a bigger hot-spot coverage then its competitors.
CPF seems to tolerate off-shore lights' baseless lumen output figures, so i'm not sure all the screaming is needed.
Surefire does define its runtime as "useful" runtime, running until there is enough light to find a key hole in the dark. By comparison many import lights have the run-until-light-suddenly-shuts-off runtime. Not good for people who don';t want to be left in the dark.
BTW the newer TIR lights have enough spill to be useful, not sure where the "needle beam" came from. In fact beyond 5-10 yards the TIR SFs have a bigger hot-spot coverage then its competitors.
CPF seems to tolerate off-shore lights' baseless lumen output figures, so i'm not sure all the screaming is needed.
maybe they are a victim of their perfectionist marketing hype? "The World's Finest" does not do an established company any good if the attention to detail for their products leave some customers less than amused. :shakehead
regulated lights should have their regulated runtimes stated, from the moment it goes out of regulation it should be stated as it is. as for output hitting 50%, i feel its rather dim for the its intended useage already. the remaining output while considered useable, may be irrelevant to some users who need the output for task at hand.
the lights are made to be dependable, the specs should follow suite. when the packaging says my E1L is made of aerospace grade aluminium, Pyrex window & weatherproof. i will like to know that it is so, without needing to personally varify them. :green:
regulated lights should have their regulated runtimes stated, from the moment it goes out of regulation it should be stated as it is. as for output hitting 50%, i feel its rather dim for the its intended useage already. the remaining output while considered useable, may be irrelevant to some users who need the output for task at hand.
the lights are made to be dependable, the specs should follow suite. when the packaging says my E1L is made of aerospace grade aluminium, Pyrex window & weatherproof. i will like to know that it is so, without needing to personally varify them. :green:
jzmtl
Flashlight Enthusiast
I don't know about you people but to me find a key hole brightness isn't "useful" brightness in a 60+ lumen light. Would be nice if they include an actual runtime plot like streamlight does. I'm sure they do it many times during product testing, so it's just a matter of making it avaliable to public.
mdocod
Flashaholic
I'm going to try to address the original question, but please bare with me this could get confusing very fast, and I've had several beers at this point..
A CR123 cell discharges most of it's energy while maintaining above ~2.25V into most loads, as it approaches being "dead" the voltage starts to rapidly fall.
Under the load of a P60L, a pair of CR123s start to sag down down in voltage after a couple hours coming up close on their point of being "dead"...
When the voltage drops to about 4.5V total, or about 2.25V per cell in a 2 cell light, the LED module drops "out of regulation" and starts feeding less current to the LED. the more the voltage drops per cell, the less current flows through the LED, and the more the runtime is "dragged" out from the cells.
The voltage continues to fall slowly, and as the voltage slowly falls, so does the current flowing across the LED. The "drain rate" from the cells keeps slowing down more and more.
The result is a light that runs for a few hours at full output, followed by many hours of diminishing output.
----------------
When you have 3 cells driving the same module, the module stays in regulation, running at about 2W all the way down till the cells have been drained to about 1.5V each. In this case, by the time the module drops out of regulation and starts reducing it's power consumption, the cells have all been very heavily depleted. So the total runtime is less because the cells spend more time keeping the module in regulation.
------------
A 3 cell light driving a P60L will have more useful regulated runtime than a 2 cell light, the SureFire runtime ratings on these lights are very misleading and they should revamp the way they are rating these lights.
-----------
does this make any sense at all?
Eric
A CR123 cell discharges most of it's energy while maintaining above ~2.25V into most loads, as it approaches being "dead" the voltage starts to rapidly fall.
Under the load of a P60L, a pair of CR123s start to sag down down in voltage after a couple hours coming up close on their point of being "dead"...
When the voltage drops to about 4.5V total, or about 2.25V per cell in a 2 cell light, the LED module drops "out of regulation" and starts feeding less current to the LED. the more the voltage drops per cell, the less current flows through the LED, and the more the runtime is "dragged" out from the cells.
The voltage continues to fall slowly, and as the voltage slowly falls, so does the current flowing across the LED. The "drain rate" from the cells keeps slowing down more and more.
The result is a light that runs for a few hours at full output, followed by many hours of diminishing output.
----------------
When you have 3 cells driving the same module, the module stays in regulation, running at about 2W all the way down till the cells have been drained to about 1.5V each. In this case, by the time the module drops out of regulation and starts reducing it's power consumption, the cells have all been very heavily depleted. So the total runtime is less because the cells spend more time keeping the module in regulation.
------------
A 3 cell light driving a P60L will have more useful regulated runtime than a 2 cell light, the SureFire runtime ratings on these lights are very misleading and they should revamp the way they are rating these lights.
-----------
does this make any sense at all?
Eric
angelofwar
Flashlight Enthusiast
I agree Eric, which is why I use my P60L in my G3 and not my G2L...I like the 5-6 regulated hours of runtime you get with the G3. You get more bang for your battery buck using the G3, if that makes any sense.
jrv
Newly Enlightened
I'm having a little trouble parsing this sentence...:green:
Which light are you talking about, and what did you see when you tested it?
Eric - yes that does make sense, even to a neophyte like me. Someday I hope to be able to do those calculations for myself so I don't have to bother someone else. 
The scenario you described never occurred to me. You see, I didn't read their website carefully and I thought they were claiming 11 hours of regulated output for the 6PL. I hate to admit I was that careless but it's the truth. I thought that sounded like an amazingly long runtime, I should have stuck with my instincts and not believed it. Thanks for taking the time to explain the situation. I agree with the suggestion that SF should supply an actual runtime graph, or at least the time until the light drops out of regulation. Total runtime only is not terribly useful to me.
Thanks again, Eric!
The scenario you described never occurred to me. You see, I didn't read their website carefully and I thought they were claiming 11 hours of regulated output for the 6PL. I hate to admit I was that careless but it's the truth. I thought that sounded like an amazingly long runtime, I should have stuck with my instincts and not believed it. Thanks for taking the time to explain the situation. I agree with the suggestion that SF should supply an actual runtime graph, or at least the time until the light drops out of regulation. Total runtime only is not terribly useful to me.Thanks again, Eric!
