# Samsung 18650 2600mah question - there are 2 versions, 26D and 26F



## bestsystem (Feb 20, 2012)

I strongy believe they are different structually due to the different weight.
but what is the difference?

http://samsungsdi.com/battery/cylindrical-rechargeable-battery.jsp

also it seems that batteries beyond 2600mah have weird high voltage, which obstructs using in as a drop-in replacement


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## andrewnewman (Feb 20, 2012)

Yes. Samsung, Sanyo and LG all make cells with > 2600Mah capacity that require chargers whose CV phase runs at either 4.30 or 4.35V vs. the more typical 4.20. You can use these batteries with a traditional charger safely but won't get the claimed capacity. Panasonic (to my knowledge) is the only company that makes a > 2600Mah battery that charges at 4.20V.


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## jasonck08 (Feb 21, 2012)

26D and 26F are likely just have slightly different chemistry compositions. Some manufactures keep the same model number even though the make a change to the cells chemistry, others create a new cell model. I couldn't find any information on the 26D cells chemistry, but I know this:

ICR18650-26F: Mixed Co/Ni/Mn cathode

ICR18650-26A: LiCoO2

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Also you are correct that most other cells above 2600mAh (with the exception of Panasonic) require higher charge voltages -- 4.3-4.35v. This is because cell manufactures basically hit a wall with the traditional LiCoO2 blend and couldn't make cells with more than 2600mAh. So they began creating "hybrid" cells adopting other materials like nickel, aluminum, manganese etc.


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## bestsystem (Feb 21, 2012)

in terms of
1. life-time, especially at 90%+ charge storage
2. robustness
3. discharge voltage curve
4. charge rate
5. any other important parameters

How different are they?


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## Shadowww (Feb 21, 2012)

jasonck08 said:


> Also you are correct that most other cells above 2600mAh (with the exception of Panasonic) require higher charge voltages -- 4.3-4.35v. This is because cell manufactures basically hit a wall with the traditional LiCoO2 blend and couldn't make cells with more than 2600mAh. So they began creating "hybrid" cells adopting other materials like nickel, aluminum, manganese etc.


How did Panasonic overcome that limitation and why can't others do the same? Have Panasonic got a patent on it or it just needs some very sophisticated technology?
Also, isn't Sanyo part of Panasonic? If it is, why are they Li-Ion offerings so different?


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## bestsystem (Feb 22, 2012)

Yeah, Panasonic does good job, pana can do 3100mah at 4.2V while others need to clamp up to 4.3v+:shrug:
anyway, has new technology improved the storage life of 3.7 V lithium rechargables?


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## jasonck08 (Feb 22, 2012)

bestsystem said:


> in terms of
> 1. life-time, especially at 90%+ charge storage
> 2. robustness
> 3. discharge voltage curve
> ...



I don't know enough about both chemistries to answer all of your questions. However I will say that generally speaking cells with nickle and manganese are often regarded as being "safer."



Shadowww said:


> How did Panasonic overcome that limitation and why can't others do the same? Have Panasonic got a patent on it or it just needs some very sophisticated technology?
> Also, isn't Sanyo part of Panasonic? If it is, why are they Li-Ion offerings so different?



Panasonic uses LiNiCoMn similar to the Samsung 26F. They just must have a special formula or some other materials that allow them to maintain the 4.2v charge voltage, yet offer the cells with 2.9Ah and 3.1Ah capacities. Panasonic bought Sanyo a couple years ago. Their Li-ion offerings are so different because Sanyo had their own line-up of 18650 cells before they were acquired. Sanyo went the higher voltage route and developed 4.3 and 4.35v charge voltage cells using different materials like LiMn2O4 (Co,Ni)/carbon.


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## Street (Feb 22, 2012)

I know 2 types of these cells, ICR18650-26F and ICR18650-26C.But there is no difference between charging voltage,weight.Both have 4,2V.

http://www.scribd.com/doc/82409098/Samsung-2600mAh-ICR18650-26C
[URL="http://www.scribd.com/doc/82409398/Samsung-2600mAh-ICR18650-26F"]http://www.scribd.com/doc/82409398/Samsung-2600mAh-ICR18650-26F
[/URL]
and 

http://www.scribd.com/doc/82410071/Samsung-2600mAh-ICR18650-26A

My first post on CPF.


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## markr6 (Oct 29, 2013)

Thread Revival!!

I just pulled two of these out of a external cell phone battery pack. So now I have two pink Samsung 18650s that say ICR18650-26FU. So, are these of any value since I can only charge them to 4.2v with my Xtar WP2, and the capacity is pretty low (compared to my 3400mAh) to begin with?


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## ChrisGarrett (Oct 29, 2013)

markr6 said:


> Thread Revival!!
> 
> I just pulled two of these out of a external cell phone battery pack. So now I have two pink Samsung 18650s that say ICR18650-26FU. So, are these of any value since I can only charge them to 4.2v with my Xtar WP2, and the capacity is pretty low (compared to my 3400mAh) to begin with?



Don't give up your day job.

I've bought from this guy in the past and he's fast and true to his word. 

He's got an eclectic batch of cells for sale and he must now be doing a lot of E-Cig sales, because he's featuring a lot of 'high current handling' batteries, like the Samsung 26F and an Samsung INR chemistry.

http://www.ebay.com/sch/Rechargeabl...IT&_ssn=r-lsales&_dcat=48619&Type=18650&rt=nc

I have an Xtar WP2 II and I just got some Redilast 17670s which use the 4.35v Sanyo UR16650ZT cell and while I won't get the capacity that 4.35/4.30v yields, it's not a huge loss.

Chris


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## markr6 (Oct 29, 2013)

Thanks Chris. In terms of "value" I just meant is it worth even using them in lights, or just throw them in the junk drawer probably never to be used. I now have more batteries than I can really use, so I'll probably just run them down and put in storage either way.


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## ChrisGarrett (Oct 29, 2013)

markr6 said:


> Thanks Chris. In terms of "value" I just meant is it worth even using them in lights, or just throw them in the junk drawer probably never to be used. I now have more batteries than I can really use, so I'll probably just run them down and put in storage either way.



If you can test them out and they're still good, I would use them, or store them in the fridge at ~3.7v, if you can't readily employ them here and now. You just never know when you might need to give somebody a light and you don't want to give them you 'best' cells. Now, if you're getting short run-times with those cells, then I might pitch them into the recycling bin.

I've been fiddling with my NiMH stash and I'm finding myself putting batteries back into remotes that get used perhaps once/twice a year, lol, just so I can use some of them.

Chris


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## hank (Sep 3, 2014)

oops, wrong thread, posted to a more appropriate one


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