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Flashlight Enthusiast
So, one day, I get a package from bwaites, and inside is a SF M3T. Cool! I thought. I'd been wanting to check this light out for a long time. Bill sent it to me with Pilas installed, actually, but I was more interested in the performance of the light when powered as intended--with 123 primaries.
So I install the MN15 and drop in three brand new SF 123A batteries. And . . . was rather disappointed. The beam was a bit cold. Not as white as I had hoped for. A definite disappointment. I guess that's why some have suggested that using the N2 LA instead of the MN15 is a cool thing to do. But I've never seen an N2 so I wouldn't know one way or another.
Anyway, I was thinking about M6 lamp choices a couple weeks ago and all of a sudden it hit me! Why not make the M3T's loss the M6's gain? Both flashlights use the exact same turbo-head, so the only difference between them is the battery configuration driving the lamp. And, if you don't already know, both the M3T and the M6 are nominally 9 volt lights, driving lamps with three series CR123A batteries. The difference is that in the M3T, there is only a single stack of three series CR123A's, but in the M6, there are two parallel stacks of three CR123A's. Or electrically there are! Physically it looks like three stacks of two CR123A's, but the MB20 battery holder electrically connects this 3p2s physical arrangement into a 2p3s electrical arrangement. And a voltmeter will confirm that the MB20 battery holder loaded with 6 CR123A's has an open circuit voltage of approximately 9 volts.
(And by the way, I will mentioned that if you remove the correct 3 CR123A's from the holder, you can still have 9 volts from a single stack of 3 CR123A's but in the form-factor of the SF M6, but with the same battery configuration as the M3T. But I digress . . .)
The point is that if the MN15 was a bit less white than it should be on a single stack of three 123's, wouldn't it be perfect on TWO STACKS of three 123's? In case you're wondering what the reasoning here, I will quickly say that the voltage under load of a battery (and especially CR123A batteries) very much depends on both the state of charge and the draw rate. Draw more current and you have less voltage at the lamp. Draw less current, and you have more voltage. And since the two stacks of 3 CR123A's in the SF M6 share the load equally, they will have half the current draw of what they would have in the M3T driving the MN15, so there will be an increase of voltage applied at the lamp. And since it is, in my estimation, a little underdriven in the M3T, I figured it would be a litter overdriven in the M6. A little, but not too much, I hoped. My hotwire intuition told me that the MN15 in the M6 should be just about perfect!
Well, sure enough, it is PERFECT IN THE SF M6. I estimate it to be the same CCT as the A2: 3300 K, which is nice and white. About the same as the MN20. Plus, the slight overdrive pushes the output up a little as well as the whiteness.
So, I would guess the MN15 in the SF M6 is about a 175 to 200 lumen LA. And I'm guessing it will run for about 2.5 hours. I'm calling it an "X-LOLA" for Extra-Low Output LA. Or Extra-long running LA.
I went out tonight and field tested the beam, and I really, really like it. It easily throws 600 feet, and puts out a decent amount of light, with a lovely, white, pleasing beam. The MN20 is definitely brighter and longer throwing, but the MN20 won't run for 2 and 1/2 hours.
The thing about 123's is that at the lower draw rates, you really start to take advantage of their superior energy density, and they have better discharge curves--i.e. they hold better voltage under load over their run time.
Chamenos actually got me into the whole extra-long running lamp thing by recommending the MN02 for the E2e. He has since un-recommended it due to the fact that he has had two of the lamps exhibit very premature blackening and has gone back to the MN03. But still, the point is that 2.5 hours of runtime is a great thing, especially when the beam is nice and white and pleasing.
The SF M6 running the MN15 is like the SF A2's bigger brother. It might as well be regulated! I have used this combo for 30 minutes so far and haven't noticed the least bit of dimming or drop-off of whiteness.
I will be testing this combination extensively over the next several weeks and will do definitive runtime tests and make some bench measurements, and so on. But for now, I feel confident enough about it to post.
And, as it turns out, SureFire will warrantee this combination, as batman posted about in post #298 of this thread! He says that:
So, that's awesome news!
However, do not run the MN16 in the M6. The MN16 is NOT underdriven on a single stack of three 123's, so two parallel stacks will push it too hard, and it might possibly flash at start-up, or have a much foreshortened life.
Thus, it is my distinct honor to introduce the "X-LOLA" SF M6 lamp configuration! Thank you SureFire for making such awesome lights!
So, to recap, I believe the stock SF M6 now has three viable LA's to use:
HOLA: MN21. 630 lumens, 20 minutes.
LOLA: MN20. 400 lumens, 1 hour.
X-LOLA: MN15. 200 lumens, 2.5 hours.
So I install the MN15 and drop in three brand new SF 123A batteries. And . . . was rather disappointed. The beam was a bit cold. Not as white as I had hoped for. A definite disappointment. I guess that's why some have suggested that using the N2 LA instead of the MN15 is a cool thing to do. But I've never seen an N2 so I wouldn't know one way or another.
Anyway, I was thinking about M6 lamp choices a couple weeks ago and all of a sudden it hit me! Why not make the M3T's loss the M6's gain? Both flashlights use the exact same turbo-head, so the only difference between them is the battery configuration driving the lamp. And, if you don't already know, both the M3T and the M6 are nominally 9 volt lights, driving lamps with three series CR123A batteries. The difference is that in the M3T, there is only a single stack of three series CR123A's, but in the M6, there are two parallel stacks of three CR123A's. Or electrically there are! Physically it looks like three stacks of two CR123A's, but the MB20 battery holder electrically connects this 3p2s physical arrangement into a 2p3s electrical arrangement. And a voltmeter will confirm that the MB20 battery holder loaded with 6 CR123A's has an open circuit voltage of approximately 9 volts.
(And by the way, I will mentioned that if you remove the correct 3 CR123A's from the holder, you can still have 9 volts from a single stack of 3 CR123A's but in the form-factor of the SF M6, but with the same battery configuration as the M3T. But I digress . . .)
The point is that if the MN15 was a bit less white than it should be on a single stack of three 123's, wouldn't it be perfect on TWO STACKS of three 123's? In case you're wondering what the reasoning here, I will quickly say that the voltage under load of a battery (and especially CR123A batteries) very much depends on both the state of charge and the draw rate. Draw more current and you have less voltage at the lamp. Draw less current, and you have more voltage. And since the two stacks of 3 CR123A's in the SF M6 share the load equally, they will have half the current draw of what they would have in the M3T driving the MN15, so there will be an increase of voltage applied at the lamp. And since it is, in my estimation, a little underdriven in the M3T, I figured it would be a litter overdriven in the M6. A little, but not too much, I hoped. My hotwire intuition told me that the MN15 in the M6 should be just about perfect!
Well, sure enough, it is PERFECT IN THE SF M6. I estimate it to be the same CCT as the A2: 3300 K, which is nice and white. About the same as the MN20. Plus, the slight overdrive pushes the output up a little as well as the whiteness.
So, I would guess the MN15 in the SF M6 is about a 175 to 200 lumen LA. And I'm guessing it will run for about 2.5 hours. I'm calling it an "X-LOLA" for Extra-Low Output LA. Or Extra-long running LA.
I went out tonight and field tested the beam, and I really, really like it. It easily throws 600 feet, and puts out a decent amount of light, with a lovely, white, pleasing beam. The MN20 is definitely brighter and longer throwing, but the MN20 won't run for 2 and 1/2 hours.
The thing about 123's is that at the lower draw rates, you really start to take advantage of their superior energy density, and they have better discharge curves--i.e. they hold better voltage under load over their run time.
Chamenos actually got me into the whole extra-long running lamp thing by recommending the MN02 for the E2e. He has since un-recommended it due to the fact that he has had two of the lamps exhibit very premature blackening and has gone back to the MN03. But still, the point is that 2.5 hours of runtime is a great thing, especially when the beam is nice and white and pleasing.
The SF M6 running the MN15 is like the SF A2's bigger brother. It might as well be regulated! I have used this combo for 30 minutes so far and haven't noticed the least bit of dimming or drop-off of whiteness.
I will be testing this combination extensively over the next several weeks and will do definitive runtime tests and make some bench measurements, and so on. But for now, I feel confident enough about it to post.
And, as it turns out, SureFire will warrantee this combination, as batman posted about in post #298 of this thread! He says that:
Sorry to double post it up, but this is news. Surefire IS warranty covering the MN-15 in the M6 as of last week. I got an RMA and am getting a free replacement MN-15 for the M6.. In fact, the rep said that they know most people are having pretty good luck with the MN-15 in the M6. A new lamp assembly for me, only cost is sending the old, burned out MN-15 back to them.
This is a case where honesty paid off and Surefire customer service is great.
So, that's awesome news!
However, do not run the MN16 in the M6. The MN16 is NOT underdriven on a single stack of three 123's, so two parallel stacks will push it too hard, and it might possibly flash at start-up, or have a much foreshortened life.
Thus, it is my distinct honor to introduce the "X-LOLA" SF M6 lamp configuration! Thank you SureFire for making such awesome lights!
So, to recap, I believe the stock SF M6 now has three viable LA's to use:
HOLA: MN21. 630 lumens, 20 minutes.
LOLA: MN20. 400 lumens, 1 hour.
X-LOLA: MN15. 200 lumens, 2.5 hours.
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