what is the difference between 26650s and 18650s

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wesco
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what is the difference between 26650s and 18650s

What is the difference between the 18650s and the 26650s. I see the 26650s ranging from 3.2V to 3.7V and 3000mAh to 6000mAh. if they are the same size of an 18650 why are they more powerfull and wouldn’t the 26650 fry my light?

Edited by: Anonymous (not verified) on 08/23/2012 - 11:01
ruffles
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Not the same size… the 26 refers to the diameter in mm. (Same length, though.)


 

gords1001
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The numbers give a rough idea of size.

18650 :- 18mm diameter, 65mm long.

26650 :- 26mm diameter, 65mm long.

You can obviously use 18650’s in a 26650 light with a sleeve, but not the other way round. I have only had my 26650’s a few weeks, but I do really like them, the lights are no where near as skinny. :bigsmile:

Default Username
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26650’s are a fair bit fatter than 18650’s. If I understand correctly, the first two digits refer to the diameter of the cell in millimeters, while the next two digits refer to the length. For example, a 18650 is roughly 18mm in diameter and 65mm in length, and likewise a 26650 is roughly 26mm in diameter and 65mm in length

No idea what the last digit stands for though :~

tatasal
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Default Username wrote:
26650’s are a fair bit fatter than 18650’s. If I understand correctly, the first two digits refer to the diameter of the cell in millimeters, while the next two digits refer to the length. For example, a 18650 is roughly 18mm in diameter and 65mm in length, and likewise a 26650 is roughly 26mm in diameter and 65mm in length

No idea what the last digit stands for though :~

The last digit 0 stands for its shape, which is cylindrical.

wesco
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Awesome I’ve just recently got into the LED light modding and hadn’t got that far yet. So thank you for clearing that up.

2100
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26mm vs 18mm.

That results in a cell that has 2X the volume of 18650. That’s no joke.

Unfortunately current R&D has only produced cells that are like “2200mAh” for 26650s, if you compare them to 18650s directly wrt vol.

sintro
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It’s just a bigger version of the 18650. It’s like AA vs AAA, just a lithium rechargeable though.

HKJ
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wesco wrote:
What is the difference between the 18650s and the 26650s. I see the 26650s ranging from 3.2V to 3.7V and 3000mAh to 6000mAh. if they are the same size of an 18650 why are they more powerfull and wouldn't the 26650 fry my light?

 

As many has explained the 18650/26650 is a size difference.

The 3.2V / 3.7V volt is a chemistry difference.

Anything marked as 3 or 3.2 volt need a charger with a maximum charge voltage of 3.6 volt (LiFePo4 chemistry).

Anything marked as 3.6 or 3.7 volt need a charger with a maximum charge voltage of 4.2 volt (LiCoO2 or LiMn chemistry), this is the most common LiIon charger.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

gords1001
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Not if you bore the battery tube 8 mm.

If you have a spare 8mm of battery tube wall, you are carrying an aluminum bar with an led in the end, not a flashlight….. :bigsmile:

Hannes
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In my option the 26650 is very disappointing. only 30% more real capacity but 100% more volume. what a waist. I wish some of the 18650 manufacture will wake up and start to use the same technology in the 26650.

http://lygte-info.dk/review/batteries2012/TrustFire%20TF26650%205000mAh%20(Flame)%20UK.html

just my 2c

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Don
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Isn’t going to happen.

Just about every laptop out there uses 18650s – as does the Chevy Volt (8192 of them AFAIR). There is a lot of competitive pressure to make higher capacity 18650s. Just about nobody uses 25650s. And they don’t fit properly in C cell lights. For every 25650 sold I’d guess a few tens of thousands of 18650s get sold.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Hannes
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Yes I realize that. Just sad because I like the size of a flashlight that houses them. It cradles very nicely in my hand.

Maybe one one day we see a China battery claiming +10,000mAh out of a 26650 and it turens out top be 6000mAh

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are actually made up of a different chemistry than 18650’s? I kinda find that hard to believe. But I’m flexible.

Maybe volume doesn’t equate to a one for one linear increase in capacity due to battery physics? I’ll let the batt experts chime in here. In any case, given my druthers I’ll take a 30% increase over 0% increase any day. In a one-hour runtime torch that’s about 20 extra minutes. Nothing to sneeze at IMO especially if it can save yer skin someday.

“When I buy something in bulk you should prolly buy at least one too.”…..“They that have light shall rule the night.”…..“Flashaholics feel depressed without darkness.”…….“I’m a very terminal torchaholic. My entire life just flashed before my eyes

Don
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Chemistry isn’t the whole story.

The details of manufacture are what really makes a difference. You can get 1600 or 3400mAh 18650s. Which one is harder to make?

What market is there for $5000 26650s? I’d guess approximately none.

That’s the sort of money that gets amortised over billions of 18650s.

An 18650 has pi*r*r*h volume – or 3.14159×9×9×65 cubic millimetres. Or 16540 cubic millimetres. For a 25650 – 312,686 cubic millimetres. Or 19x the volume of an 18650. So the best cells ought to be able to do 3400×19mAh – or 64Ah. Want, want, want quite a lot of those.

Even if they cost 19x as much as 3400mAh 18650s – so say $200 each.

How many of those would you buy?

Given that they are unlikely to last more than three years?

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

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26650s have really good capacities!
It’s only the approximate size of a C cell. Remember the maglites that used C and D cells?

for comparison see HKJs comparator. Even though it says 18650 comparator there are some 26650s on there, even KingKongs in ICR and INR chemistry.

wesco wrote:

I see the 26650s ranging from 3.2V to 3.7V and 3000mAh to 6000mAh.

Don’t believe 26650s that say 5000mAh or 6000mAh. At least I haven’t seen any true ones yet with those capacities.

נֵר־לְרַגְלִ֥י דְבָרֶ֑ךָ וְ֝אֹ֗ור לִנְתִיבָתִֽי   (Psa 119:105)   

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Look at it this way. I can buy a King Kong 26650 4000mAh for around $9; An XTAR 18650 2600mAh costs about the same. The KK has tested capacity of 4400mAh, The XTAR, 2600mAH on a good day. If I use the XTAR on a  2 hour ride, I'm going to have to switch cells a little over 1/2 way through the ride. The King Kong gives me close to 2 hours run time with a brighter flashlight. 26650's are great for cycling - I wish I had more choices in lights.

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a real-world difference. I like those the best.

“When I buy something in bulk you should prolly buy at least one too.”…..“They that have light shall rule the night.”…..“Flashaholics feel depressed without darkness.”…….“I’m a very terminal torchaholic. My entire life just flashed before my eyes

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Don wrote:
Chemistry isn't the whole story. The details of manufacture are what really makes a difference. You can get 1600 or 3400mAh 18650s. Which one is harder to make? What market is there for $5000 26650s? I'd guess approximately none. That's the sort of money that gets amortised over billions of 18650s. An 18650 has pi*r*r*h volume - or 3.14159x9x9x65 cubic millimetres. Or 16540 cubic millimetres. For a 25650 - 312,686 cubic millimetres. Or 19x the volume of an 18650. So the best cells ought to be able to do 3400x19mAh - or 64Ah. Want, want, want quite a lot of those. Even if they cost 19x as much as 3400mAh 18650s - so say $200 each. How many of those would you buy? Given that they are unlikely to last more than three years?

Its actually 26650 and roughly 35500 cubic millmeters. Thats ~2.09x volume, so we could have 26650 cells with ~6000mAh now.

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Don wrote:
Isn't going to happen. Just about every laptop out there uses 18650s - as does the Chevy Volt (8192 of them AFAIR). There is a lot of competitive pressure to make higher capacity 18650s. Just about nobody uses 25650s. And they don't fit properly in C cell lights. For every 25650 sold I'd guess a few tens of thousands of 18650s get sold.

Hmm... A new chevy volt battery costs around 10,000 dollars, do you have any idea what capacity the 18650s are? Big Smile

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Does anyone know what the highest capacity 26650 is out there? I know most of the higher capacity claims are false, with both 18650 & 26650. Are those 4400 king Kongs the top of the real capacity mark? I’d like to buy 3 or 4 of them but not sure where to find them? Any ideas thanks

When in doubt…..More Power!

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The difference? 8 silly millimeters. Wink

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Hannes wrote:
In my option the 26650 is very disappointing. only 30% more real capacity but 100% more volume. what a waist. (…)
Well, i have to object:
My preferred A123 systems 18650 (APR18650M1A) has a capacity of 1100 mAh.
The corresponding A123 systems 26650 (ANR26650M1B) has a capacity of 2500 mAh, that’s more than twice!

…but maybe, other producers didn’t do their homework? :~

Aloha, Uli

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NightCrawl wrote:

Its actually 26650 and roughly 35500 cubic millmeters. Thats ~2.09x volume, so we could have 26650 cells with ~6000mAh now.

Compared to the 3400mAh Panasonic 18650 you could probably make a 7000mAh 26650…

Anyone want to do the maths on a 32650 and 32500?

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I have a similar light. I am using a 16650 and it works great, although there is plenty of room left for a fatter battery; however, the inside diameter of my light is only 2400 and NOT 2665(0). Take the light to your vape or battery shop and try it out to be sure it fits, because you cannot return batteries after the sale (or in most stores anyway).

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18650s make a smaller light for carrying than 26650
26650 is for more energy and power
but they are WAY more expensive
plus 18650s are also available ‘free’ – if you take apart laptop packs

i find 18650 has plenty of energy and power

wle

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26650’s are not more expensive, they are about the same price as 18650’s and when considering their energy, even cheaper.
For flashlight use they are preferable IMO, as their size fits better in a man’s hand.
Once you’re used to them, you’ll find a 18650 light something more for women.

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Enderman wrote:
MRTdiver wrote:
Don’t believe 26650s that say 5000mAh or 6000mAh. At least I haven’t seen any true ones yet with those capacities.
There are 5000mAh and 6000mAh ones. Literally right in the link that you yourself posted.

That was 2012 he posted… Back then I was so young and handsome… Hold on, I’m still young and handsome, never mind carry on lads!

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hIKARInoob wrote:

That was 2012 he posted… Back then I was so young and handsome… Hold on, I’m still young and handsome, never mind carry on lads!


My bad for not looking at the date.
hIKARInoob
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Well it was an unusual necro thread bump by someone with only one post (#25)… really odd…

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hIKARInoob wrote:
Well it was an unusual necro thread bump by someone with only one post (#25)… really odd…

A one-post-wonder too. Facepalm