Surefire M6 / MN20 LOLA / 2x IMR 18650 cells?

[Ty_Bower]

The title pretty much says it all. I'd like to know if the MN20 lamp is fairly safe and reliable when driven by a pair of IMR 18650 cells. Given the price of these lamp assemblies, I'd rather not be running a high risk of insta-flash. Would I be better off sticking with conventional lithium cobalt based rechargeable cells?

[Ty_Bower]

I found one reference... sounds like it's not a good combination. Can anyone else offer any experience?

Having blown a few MN20 LAs in a light with some IMR 18650s and IMR 2x2500 and ruining some KT1/2 heads I understand where people are coming from.

[Steve in SoCal]

I usually run an mn20 in at least one of my M6s since the light output is ok and the runtime is reasonable. I typically run it off of a pair of AW18650 2600 or 2900 black cells.As you have found, some people have had bad experiences running an mn20 off iMRs. I personally wouldn't use imrs just because of the short run time (unless you have fivemega's 2x26500 body extension). As a side note the old generation purple bodied mn20 bulbs were very fragile and tended to blow easier.

[Ty_Bower]

I'm running the newer 14 turn MN20 lamp assemblies. I know the old purple base MN20 are delicate, but I don't have any of those.

So, I've crossed IMR off my list. How about the recent Panasonic NCR 2900 or 3100 mAh cells? Those things sure can push a lot of amps, at least 5 or 6 on a good day. Are they gonna eat my MN20?

[Flea Bag]

Those newer cells should be fine. I've been using MN20-2x18650 (older 2200mAh AW versions) as my bread and butter setup for quite a while. The newer cells may have around about or close to 40% more energy and so will put out more current but they're also lower nominal voltage at 3.6 vs 3.7v of the smaller capacity cells so if you're concerned about them being overdriven, perhaps that may help a bit. My MN20 has over 30 hours on it and though the beam is a little more yellow with age, it's still quite very nice. I certainly don't notice yellow or brown deposits on the glass envelope as with some of my other older bulbs like my P90.

I hope someone else jumps in to give impressions or if you have time, you could wait for me to try the cells myself. I plan to have them in two to three weeks time and can test them on my old MN20 as well as a newer one to note runtime differences, tint and so on.

[325addict]

I surely would stick with LiCo based cells, as these simply cannot deliver a very high instantaneous peak current (it is THIS current that instaflashes a bulb!)
I used my MN20 for extended periods of time on two older Samsung unprotected Lithium Cobalt cells. But the AW 2600s are also very well suited, I used these ones also. Until now, I never flashed a bulb in my M6. Neither a SureFire bulb (MN15 or MN20), nor a Lumens Factory bulb (which are excellent replacements when SF has discontinued the MN20).
I hope this helps...