SF M3 + MN11 + 2x17500, what runtime?

[defusion]

I just ordered a surefire M3 on ebay with both the MN10 and MN11 lamp assemblies. I plan on this being a backpack light, my light on my body will remain my fenix, but i want something with a bit more punch (especially throw-wise) in my backpack which i carry most of my time away from home.
Now i'm wondering what runtime i can expect while using the 225 lumen MN11 lamp assembly with 2x17500 batteries.

 

[Flash007]

I think 2x17500 cells will be a little weak, or just OK for continuous use with the 225 lumens LA.

Current draw from MN11 must be ~2.2A minimum, and the 1100mAh cells can draw only 2.2A safely.

If the Surefire flashlights could accept 18500 cells (1500mAH but thicker), no problem for the MN11. But unfortunately, it's not the case.
Surefire bodies are 17mm, and accepts only 17500/17670 cells.

It's why I have ordered W-E flashlights (thanks to Unforgiven and PTS-Like) wich accept 18500/18650 cells.

 

[pete7226]

You're much better off with at least 2 18500's, or get yourself a leef 2x18650 body or bore it out yourself add a a19 and use 2x18650. I have this setup and it runs much whiter and lasts about 35-40 minutes before noticeable dimming.

 

[mdocod]

2x17500 will run for about 15 minutes, and unfortunately, is NOT safe. The MN11 draws 2.5-2.7amps. minimum safe cell size for a MN11/P91 is 18500. bore the body, or add an extender to run 17670s, or do both boring and extending to run 18650s like pete said.. the leaf body is the best solution for this...

This is the very reason I tend to recommend people start with Wolf-Eyes products if they are interested in rechargeable solutions. Or piece together the final product: IE: order the turbo head and switch from SF, and order a 18mm body with SF compatible threads from someone else. This way you don't have an expensive piece of aluminum tube laying around collecting dust.

 

[Owen]

I've got an M3 on the way as well, and plan to use it with the MN11. I saw where someone sold one awhile back that was bored for 18500s, and figured to do the same(though I'm a bit nervous about the wall thickness since it'll be around .044"/1.1mm if the dimensions are the same as my Z3s). I don't expect more than 20-25 minutes with 1400mAh 18500s. I've used 2x17500 with various 9V LAs pulling from .8-1.5A, but have no plan to do it other than momentarily with a lamp with current draw as high as the MN11. I wanted higher output than the lamps I use in the Z3, with the same form factor, and a floodier beam than the Lumens Factory lamps offer, so really didn't have many choices.
The only other option as I see it(for a 3x123 body) is a Leef 2x18500+C-M adapter, and that's getting up there in price for just a body, since the adapter is fairly expensive itself.
I really prefer the Combatgrip bodies with flats on the sides for indexing oval beams, anyway, so will take a chance with having the M3 bored, since I'll actually use it all the time.
Lumens Factory is supposed to be releasing aftermarket lamps for the M3 in the near future, and I'm hoping they come up with something between the MN10 and MN11 for a good compromise between brightness and runtime. That's actually the reason I went ahead and sprung for a M3...along with tacticalsupply closing out their inventory, and the fact I always wanted one.
Hard to resist all those excuses to buy

 

[cmaylodm]

You know Leef makes 2x18650 C-tail M-heads right? No need for an adapter with that one. I hear what you're saying about buying the M3 though, with the tacticalsupply.com sale I had to pick myself up an M3T-CB! :rock: I'm thinking about getting one of the aformentioned Leef bodies and an AW tower module + Seoul USVOH + Downboy 1000. What an addiction...

 

[Owen]

Yeah, but that's not a 3x123 length light
I've got one of the C-C 2x18650 bodies with a KT2 running a MN21 for my "big light", but it isn't something I carry around.
I started to go for a M3T while I was at it, since that's sort of my dream light, but know from having a Z3/SRTH that I won't carry a turbohead even on a smaller body.
This flashlight stuff sure is fun, though!

 

[cmaylodm]

Oops, my bad. I have a habit of reading through posts a little quickly at times.

and on that note...
I am finally an official CPF flashaholic!

 

[defusion]

One more question; is the tailswitch still easily reachable when using a cell extender? or do you have to resort to a weird grip style for that to work the way it should?
Also, how easy is it to properly bore the body out? What kind of machinery would i need?

 

[mdocod]

I think to do a proper bore, you'll need a lathe, investing in a $4000 tool to bore out a $300 flashlight might be a little overkill unless you wanted to make a hobby of boring flashlights... A machine shop in town might be able to help out- or a fellow CPFer.

 

[defusion]

I think to do a proper bore, you'll need a lathe, investing in a $4000 tool to bore out a $300 flashlight might be a little overkill unless you wanted to make a hobby of boring flashlights... A machine shop in town might be able to help out- or a fellow CPFer.

ah yeah, thats a bit overkill

I'll probably get an extender and use the 17670's, but how would this work exactly? can i still easily hit the tailswitch with my thumb?

 

[Owen]

I doubt it. I would never put an extender on a CombatGrip light, personally. A lot of people around here do, apparently, but it defeats the purpose of the CombatGrip, and looks stupid as crap, too.
I just sent a C2 body to CPF member highorder to bore out for an 18650, and may send my M3 and a Z3 to him before it's all over with. I know a guy who runs a machine shop, though, and may just get him to do it, but only see him every month or so...
I already have 4 Wolf Eyes 18500s on the way, and nothing to use them in, so there's a little incentive

Anyway, I got my M3 before leaving for work today, and gave the 17500s a shot with the MN11 tonight. They did better than I expected.
I was only doing 3 minute runs, because I frankly didn't expect them to last long, and didn't know if overheating the batteries or whatever would be a concern. Besides, most of my use, especially with a light this bright, tends to be very short, from a momentary flash to maybe a couple of minutes most of the time.
I use AW's protected 1100mAh 17500s. They needed a double tap/twist to light the MN11.
The batteries went into protection mode at 26:59, just as I was about to turn the light off from its ninth 3 minute run. On the eighth run there'd been very noticeable dimming, and though the spot was still brighter at the beginning of it than the Wolf Eyes 9V D26 lamp in my Z3, the overall output was quite a bit less. It was still very usable, right up until the last run, when it dimmed rapidly, and then shut down.
Kind of wish I'd compared brightness after each run, so I'd have a better idea of how the brightness drops off, but oh well.

The MN10 surprised me, since I expected it to be more flood oriented, and it turned out to have a strong spot, and relatively weak spill compared to the 9V D26. Reminded me very much of the Lumens Factory HO-9.
Think I'll be sticking with the MN11, anyway, and leave the MN10 in the SC2 in case I need to run off primaries.

Man, I love this light. Should have bought an M3 years ago

 

[Flash007]

I doubt it. I would never put an extender on a CombatGrip light, personally. A lot of people around here do, apparently, but it defeats the purpose of the CombatGrip, and looks stupid as crap, too.

You can always but an DETONATOR extender for Surefire @Lighthound :

http://www.lighthound.com/index.asp?PageAction=VIEWPROD&ProdID=1102

You keep the CombatGrip function, but it does the flashlight a little bigger, but very "sexy" !
Look at this post :

https://www.candlepowerforums.com/threads/132763&highlight=detonator

 

[defusion]

You can always but an DETONATOR extender for Surefire @Lighthound :

http://www.lighthound.com/index.asp?PageAction=VIEWPROD&ProdID=1102

You keep the CombatGrip function, but it does the flashlight a little bigger, but very "sexy" !
Look at this post :

https://www.candlepowerforums.com/threads/132763&highlight=detonator

But if i were to put it on the M3, it would sorta be a dual-combatgrip.
anyway, i'm ordering some 17500's, 17670's, and the detonator extender. that should cover everything for now.
maybe i'll get a turbohead + 2x18650 body for it in the future, and i can mess around even more (add a tailswitch and i have 2 complete lights even)