21700 Malkoff possibility

21700 Malkoff?

  • 21700, it's time for even longer regulated runtime

    Votes: 46 75.4%
  • 18650, it's compact, and it's already enough

    Votes: 15 24.6%

  • Total voters
    61

thermal guy

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Not being in the machining business I’m definitely not an expert but a 2X21700 is just a longer tube. I’m assuming everything else stays the same. I would think it’s a easy thing to make. It’s probably a matter of will they sell or not. I’m thinking it would. I need at least 2 I really want one for my V4 wildcat. I get 1 hour 45 minutes off of 2X18650’s Probably get 30-45 minutes more with the 21700’s.
 

etc

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it would have the same runtime as a 3x18650 device, I have that config on my Hound Dog Super.

2x21mm would be a lot more compact.
 

thermal guy

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I haven’t done the maths. On the runtime. 2X2170 would be the same as 3X18650’s? this is also my setup.
 

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etc

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Yes, basic math suggests just that. Run the numbers.
3.7V * 5000mAh * 2 = 37Wh

3.7V * 3500mAh * 3 = 38.8Wh

You can use either 3.7V or the fully charged 4.3V, either way the math is the same. About 40Wh

Roughly equal, especially given 5000 mAh for a 21mm cell is conservative. Once they come out with 5500 mAh, it's ahead.

and 2 21mm cells are a lot more compact than 3x18650, which is huge.
 

thermal guy

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Ya but what about draw? She draws a lot less with 3X18650 then 2X21700’s.

a 2X21700 should be 1.5 inches shorter then a 3X18650 so ya it will be a bit shorter. Either way im in for one.
 
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etc

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Well, 3x65mm = 195mm
2x70mm=140
the delta is 55mm or 2.1"

By going to the two 70mm cells you save 2 inches. Assuming everything else is the same.

The cells are almost identical in length, there is a 5mm difference, or 0.5cm (or 1/5 inch)
 

thermal guy

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could be I just measured mine to get that number of 1.5 inches. My 3X18650 and then doubled the length of the 21700 body on my super.
 

CHNeal

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So i just read thru this entire thread and as could be expected…I just ordered a 21700 body for my M61HOT. I am just as interested in the larger gripping surface as I am the run time. The MD2 pineapple is just to small and slippery for a positive grip in my hand. Hoping the increase in diameter will help and the added runtime is gravy! The battery is cheap enough and my charger already handles them so why not give it a try. I figured worse case Ill make someone a great deal on a slightly used 21700 body. And if does work like expected put me down for 2-2x21700, one for my hound dog and one for the wildcat.
 
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CHNeal

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21700 body arrived today and to say I am pleased is an understatement. The added diameter brings the pineapple grip to life. I actually really like it on the body but traded it away on both the MD4 and MD2.
I think it is too small for the Hound Dog or Wildcat ( length wise anyway) so I will holdout for the 2x21700 for those lights instead of ordering 18650 versions of those to put on this body.
I like the feel and heft of this with the M61HOT and believe this will become my go-to light of this type. The only thing I would change would be a brighter low then 5lm. If had the same low as the M91T has this light could actually be the only light I would carry but the high and low are just too far apart so ill need to keep a utility light on me for ordinary tasks. I will test this with a M91T H/L and see what that brings but I’m guess ing the low of the 91 will be greatly diminished with this single cell.
Who knows maybe one day we will see 21mm replacement for the 18500 and a MD3 size body for it.
A26B7437-CAF5-4493-98CA-8B6F0A7D70FA.jpeg
 

Cree XHP 70 LED

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I just got off a 30 minute call with Gene. The 2 x 21700 bodies are coming. Like everyone else he is feeling the supply chain shortage on several things, but he hopes to have them out around Christmas time if all goes well. I will wait for the 21700 bodies myself for the Hound Dog Super and the Wildcat.
 

PoliceScannerMan

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Just ordered a 1x21700 body. It will come in handy, probably didn't need it. But the thought of running my M91T head on it or my M61NLLLL for runtime was just too much to keep my finger off of the trigger LOL.
 

electromage

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I'm all for more options and more energy density - the thing that keeps me from buying/carrying a Malkoff is the size. Even the MDC 1xCR123 is a bit longer than my 18650 Zebralight. Their 18650 lights are over 2" longer.
 

thermal guy

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Just ordered a 1x21700 body. It will come in handy, probably didn't need it. But the thought of running my M91T head on it or my M61NLLLL for runtime was just too much to keep my finger off of the trigger LOL.
I got 61 hours on high and 11 days on low with my 4L and a 18650/3500 mah. So with a 5000 mah you would be set for a LONG time
 

Cree XHP 70 LED

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I'm kinda old school and have 123a 18650 and 21700 lights, I like to mainly buy lights that can use 123A cells in a pinch or emergency. However, it just occurred to me if I go with the 21700 x 2 bodies or even 21700 x 1 body, those spare 100 SF123A cells aren't going to work in those larger bores. So now I'm wondering if I would rather have the 18650 bodies.
 

thermal guy

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I just got off a 30 minute call with Gene. The 2 x 21700 bodies are coming. Like everyone else he is feeling the supply chain shortage on several things, but he hopes to have them out around Christmas time if all goes well. I will wait for the 21700 bodies myself for the Hound Dog Super and the Wildcat.
I know what I’m getting for Christmas 😁
 

wayben

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I love my 1X21700 body with Wildcat head, very cool light. Can't wait to try a 2X21700, I'll be jumping on one as soon as they're available. Variety is the spice of life!!!
 

CHNeal

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The only issue I have with the single 21700 is it doesn’t allow me a high enough low on the M61HOT or the M91 B-T heads I own. I will eventually put a 18650 Wildcat head on it and put it in my wife’s glovebox.

I will however be buying 2 ( If you guys save me any) of the 2x21700 for my hound dog and Wildcat. Its not even really about the extended run times, although those are an obvious plus, for me its more of a ergo thing. I really like the diameter of the body and it really makes the pineapple style come to life. A lot of my flashlight usage is with gloved hands and the bigger size really helps.
 
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