I'm wondering if this is a valid statment

[DapperDan]

I started a thread on another forum asking about lights using 18650 batteries and I got this response. Would you agree with this?

Originally Posted By Elzetta:
We can assure you from rigorous testing and analysis that a larger bore diameter significantly increases the stress on the batteries under impact.
Thus no premium weapon light manufacturer uses large bores that accomodate 18650 cells.

 

[greenLED]

I started a thread on another forum asking about lights using 18650 batteries and I got this response. Would you agree with this?

Originally Posted By Elzetta:
We can assure you from rigorous testing and analysis that a larger bore diameter significantly increases the stress on the batteries under impact.
Thus no premium weapon light manufacturer uses large bores that accomodate 18650 cells.

Makes sense, if you think as "larger bore diameter" as meaning larger internal diameter. Larger internal diameter= thinner walls (assuming outside diameter is the same).

 

[DapperDan]

Well I'm pretty sure Olight and Fenix consider themselves premium weapon light manufacturers and they make lights that take the 18650 batteries. I did not see any disclaimers that using this light significantly increases stress on the battery if impacted.

 

[MerkurMan]

Perhaps they were talking about the impact forces on a smaller 123-sized cell when used in a larger diameter housing. That would make sense, seeing as how the extra wiggle room would increase the cell's acceleration in to the tube wall upon impact. :shrug:

 

[berry580]

what impact would managed to put significant stress on the light's batteries? Run over by a tank? Or taking hit from a bullet?

 

[Marduke]

Makes sense, if you think as "larger bore diameter" as meaning larger internal diameter. Larger internal diameter= thinner walls (assuming outside diameter is the same).

I believe the statement is with respect to damaging the cells, not the light. The larger internal bore diameter means the 123 cells have more room to move laterally during an impact.

While I have witnesses damage to 123 cells from impact inside the light, I do not personally believe the extra 2mm of bore diameter would have made a difference due to the nature of the damage.

 

[DapperDan]

what impact would managed to put significant stress on the light's batteries? Run over by a tank? Or taking hit from a bullet?

That's a good question I don't know. The manufacturer of Elzetta told me that "no premium weapon light manufacturer uses large bores that accomodate 18650 cells".

 

[MrGman]

Well I'm pretty sure Olight and Fenix consider themselves premium weapon light manufacturers and they make lights that take the 18650 batteries. I did not see any disclaimers that using this light significantly increases stress on the battery if impacted.

They are talking about stress to the battery not to the flashlight walls. I am of the belief (although they didn't state it here) that they are specifically worried about the stress to the original size CR123 battery with a 16mm diameter in an 18mm tube for those who would still use primaries such as military and law enforcement personnel. Having the extra free space gives the battery more room to move around before it slams to a stop causing greater shock from things like gun fire and dropping the flashlight on hard ground, such that the batteries would cave in and fail. I can believe that this would be a true statement. So if I understand their meaning, they are saying they don't want to make the battery compartment any large than necessary to accomodate the standard CR123 battery type to minimize any acceleration on the battery and therefore limit damage to a pair of CR123 sized cells by not giving them the room to accelerate. And from what I have seen in my own experience I can believe this is the smart thing to do.

Other companies that want to make the feature of an 18650 or 2X18650 type battery option but aren't marketing the light as a military ruggedized type product specifically, or knowing that their customer would actually use the 18650 size cells and not have the empty space wouldn't have this issue.

Elzetta probably has done some shock testing and seen that 16340 sized cells in a 18mm tube get beat up and its not worth the risk.

If you want the 18mm tube go with the original MD2 type host.

 

[csshih]

hmm, I heard somewhere of someone having cr123a cells being "crumpled"? in a weapon light

i'd imagine the extra lateral space would allow for that.


edit: yeah, what MrGman said

 

[DapperDan]

Re: I'm wondering if this is a valid statment
[QUOT

I believe the statement is with respect to damaging the cells, not the light. The larger internal bore diameter means the 123 cells have more room to move laterally during an impact.

While I have witnesses damage to 123 cells from impact inside the light, I do not personally believe the extra 2mm of bore diameter would have made a difference due to the nature of the damage.

The statement is in regard to boring out a 123 light to accommodate a 18650 battery and because the wall is thinner it will significantly increases the stress on the batteries under impact. i can live with that but the statement that "no premium weapon light manufacturer uses large bores that accommodate 18650 cells" is what I'm really inquiring about.

 

[berry580]

Re: I'm wondering if this is a valid statment
[QUOT

er.... i think the term "premium" is the controversial word.

To many non-flashaholics, a $30 Ultrafire is quite "premium".

 

[Marduke]

Re: I'm wondering if this is a valid statment [QUOT

The statement is in regard to boring out a 123 light to accommodate a 18650 battery and because the wall is thinner it will significantly increases the stress on the batteries under impact. i can live with that but the statement that "no premium weapon light manufacturer uses large bores that accommodate 18650 cells" is what I'm really inquiring about.

Well, they could arguably be coming from the perspective of supplying weapons lights to the US Military, which automatically excludes many of CPF's favorite manufacturers such as Fenix and Olight, etc.

They are most likely thinking "SureFire and us" when they make that statement.

 

[DapperDan]

Re: I'm wondering if this is a valid statment [QUOT

Well, they could arguably be coming from the perspective of supplying weapons lights to the US Military, which automatically excludes many of CPF's favorite manufacturers such as Fenix and Olight, etc.

They are most likely thinking "SureFire and us" when they make that statement.

Well that's what I was kind of thinking. Surefire and us. I'm betting my M20 Warrior using a 18650 battery mounted on my Colt 6920 will survive just fine.

 

[MaxIcon]

I've got a Fenix TK11, which is bored for the larger cells, mounted on a Winchester 1300 Defender, and I've probably put 250 or so rounds of 12 gauge under it - buck, slugs, and bird.

I consider this a fairly tough test platform for a flashlight - much more so than the AR, which is what Elzetta mostly sells for.

I just pulled the batteries (Panasonics CR123 lithium primaries), and they look fine. The front battery has an impression on the base from the rear battery's positive terminal and is a bit dented in, but I can't imagine that would be any different with a smaller internal diameter like the TK10. The denting is centered and even, and neither of the batteries shows any sign of crumpling to the side.

Just one data point, for sure, but it's mine, so I'm fond of it!

 

[yellow]

I think You are all wrong,
what "they" mean with the "bore" and the "18650" is the MASS of the 18650

Of course the big, heavy cell puts more stress on everything (including itself) as compared to lighter batteries - especially if it is recoil
(movement parallel to the flashlight body)

Any real sturdy light, produced to be used for shooting illumination, should offer springs on both ends.
1. no chance to loose contact
2. greatly decreases impacts, if not totally filtering them out


PS: reality shows, that that is all theoretical and even those "too large and too heavy" 18650s stand that abuse

 

[copperfox]

Originally Posted By Elzetta:
We can assure you from rigorous testing and analysis that a larger bore diameter significantly increases the stress on the batteries under impact.
Thus no premium weapon light manufacturer uses large bores that accomodate 18650 cells.

Unless by "larger bore" they mean something the size of a D cell, it's a bogus statement. 18650s are only 12.5% larger in diameter than CR123a's.

Surefire is one of the most well known weapon light mfgr's around. The stock 6P tube can take a 17670, is Elzetta going to have a cow about this larger-than-stock cell too? Come on. Any reasonably designed cell can take the force of recoil. The "no premium weapon light manufacturer" line is garbage. The Eagletac T100C2 MKII is being used on AR-15's with 18650 cells as we speak.

 

[jankj]

To me, the statement in question proves nothing but that prime quality / high price manufacturers are quite capable of producing marketing bullshit...


I think most manufacturers of prime quality / high price equipment would hate to admit that they could have done ANYTHING any other way. If they use 16 mm tubes with CR123A's then they will claim that this is the only thing that really works in though environments. Which is hard to tell until you try it, isn't it? I am sure if they actually HAD tested 18650 with inconclusive negative results they would have told the OP.


On the other hand, putting 16 mm batteries in a 18 mm tube seems to be a pretty bad idea if you want to make sure nothing can go wrong ... If battery flexibility is important, why don't manufacturer make a removable sleeve out of a 1 mm thick material?

 

[Search]

The statement is so wrong and right it's hard to want to reply to it.

- It's right because it's true.

- It's wrong because it's only true because they wanted it that way.

Making light 1 mm thicker and then boring them 1 mm thicker would give you room for 18650 and cr123.

If you manage to impact a light hard enough to damage the cells from moving inside, you probably have bigger worries. That has to be a VERY hard impact.

 

[Kiessling]

I don't know the tech stuff, but I do remeber the stories about the famous PK "Beast Toss" where pk smashed a SF Beast repeatedly into concrete. What eventually made it go dark where crushed batteries. CR123 batteries.

So .. damage to cells can happen and it need not be a plane crash to make it happen.

bernie

 

[Search]

I don't know the tech stuff, but I do remeber the stories about the famous PK "Beast Toss" where pk smashed a SF Beast repeatedly into concrete. What eventually made it go dark where crushed batteries. CR123 batteries.

So .. damage to cells can happen and it need not be a plane crash to make it happen.

bernie

He had to smash is repeatedly. How many times? This could be 3 to 999999 times.

If you have to beat a light as hard as possible against a very hard surface for an hour then it's still safe to say that worrying about this in real life isn't going to be an issue.

It's something to consider. What can it handle, but what are the odds I'm going to encounter the perfect conditions.