Does the 26670 actually exist?

nzoomed

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Im working on some custom builds and see the term 26670 thrown around alot. Problem is I dont see any batteries advertised as this anywhere on ebay.
Also when i refer to 26650, people seem to respond to me as 26670 that im talking about and have been told they are 72mm long and not the 65mm I was expecting.
I have also been told they wont fit in most lights that accept C cells, yet a C cell is supposed to be 26.2mm diameter and these are only supposed to be 26mm?

Am i missing something here?
I know alot of protected cells are sometimes a little bit longer, so perhaps this is what the discrepancy is here?
 

csshih

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those numbers generally refer to the bare cell, but some manufacturers just add it into the numbers, so yes, a 26670 generally refers to a protected 26650.
 

nzoomed

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those numbers generally refer to the bare cell, but some manufacturers just add it into the numbers, so yes, a 26670 generally refers to a protected 26650.

OK that makes sense, this was what I was suspecting.
 

HKJ

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those numbers generally refer to the bare cell, but some manufacturers just add it into the numbers, so yes, a 26670 generally refers to a protected 26650.

From 26650 to 26670 there is only 2mm, that is a very compact protection. The 2mm may be a button top.
To support protected 26650 cells you need up handle up to 71mm long cells.
You can find actual sizes of 26650 cells here: https://lygte-info.dk/info/batteryIndex.html
Checkmark size and select 26650, then click on the length column to sort.
 

fmc1

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The Orbtronic 26650 button tops are almost exactly that length. I just measured one 66.9mm to be exact. Unfortunately they are out of stock on them. I originally bought them for a two 26650’s in series application and I could not be more satisfied. I’m just sorry I did not buy more.

Frank
 

nzoomed

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From 26650 to 26670 there is only 2mm, that is a very compact protection. The 2mm may be a button top.
To support protected 26650 cells you need up handle up to 71mm long cells.
You can find actual sizes of 26650 cells here: https://lygte-info.dk/info/batteryIndex.html
Checkmark size and select 26650, then click on the length column to sort.

I thought it would be more like 7mm difference? 26650 is 65 mm long I thought, if the 72mm figure is anything to go by?
Again, from what ive been reading, its all to do with protection circuits and button tops etc. Would mean that there is a 14mm extra in total.

Im actually happy if the cells are 72mm long as it means I dont need to shorten my host at all to fit 2 of these inside.
 

fivemega

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I have also been told they wont fit in most lights that accept C cells, yet a C cell is supposed to be 26.2mm diameter and these are only supposed to be 26mm?
Each battery has nominal sizes which may be slightly difference than actual and accurate numbers.
26xxx has approximately 1mm larger diameter than C cells which is nominaly 25500

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csshih said:
those numbers generally refer to the bare cell,
That is also true but again, nominal size and not absolute size.
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I thought it would be more like 7mm difference? 26650 is 65 mm long I thought, if the 72mm figure is anything to go by?
Again, from what ive been reading, its all to do with protection circuits and button tops etc. Would mean that there is a 14mm extra in total.

Im actually happy if the cells are 72mm long as it means I dont need to shorten my host at all to fit 2 of these inside.

All numbers are just references and not actual and exact measurement. You will see same differences in alkaline or other type of cells from different brands.
Protected cells are longer and fatter than bare cells because:
1- Protection board does add some on length and size of this board are different than other makers or brands.
2- Button top also add some on length and thickness of this boards are different than other makers or brands.
3- Protection board does add some on diameter of cell because of strip for powering circuit also thickness of extra plastic heat shrink and brand label.
BTW, 2mm difference is for 65mm versa 67mm which is again theoric and not actual.
Keep in mind each cylindrical cell is NOT an accurate cylinder and diameter of one side could be slight different than other side and angle.

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