# Samsung 40T 21700



## Christos

I want to start a thread to share my experience so far with the Samsung 40T.

I believe the 30Ts have better amp ratings but these 40Ts are proving to be an all day battery for me (11ml off 0.2ohm and still above 3.4v) and I haven't experienced any sag yet. 
If you have a 21700 capable mod and are looking for some better battery life I would recommend considering the 40T.

Directly from Mooch's Facebook. 

Bench Test Results: Samsung 40T 4000mAh 21700 Retests...an incredible 25A/30A battery

Bottom Line: This cell outperforms every 18650 and 20700 in regulated devices at up to about 20A-25A (60W-75W), but in my opinion it is now not a 30A battery.

The cells I just retested ran a bit hotter than the ones I tested in Dec, 2017, which just made it to a 30A rating. I can’t give the 40T and its rewraps a true 30A continuous rating any longer. But, I will give the 40T a temperature-limited rating of 30A as long at the cell is kept below 80°C.

When the datasheet becomes available I will adjust the rating if necessary. This can include removing the temperature-limited rating if one is not in the datasheet.

At above 20A-25A/60W-75W the Samsung 30T is the better performer anyway. The 40T is best at low to mid power levels where it can be the most efficient. At higher power levels its internal resistance, about 25% higher than the 30T’s, causes more voltage sag than the 30T. The 40T is still an amazing 25A/30A battery though!

If you are running your mod at 60W-75W per battery you will have to try both the 30T and 40T to see which performs better for the way you vape. It’s just not possible to predict. 

Since the 30T and 40T are in the same family of Samsung cells, and without a datasheet being available to confirm the actual rating, I am giving the 40T a rating that brings it to about the same temperature the 30T reaches at its rating. I am estimating this cell’s ratings to be 25A with a temperature-limited rating of 30A (if kept below 80°C) and 4000mAh.

Two cells were purchased for the purposes of testing by me from IMRBatteries.

Ratings graphic: 

Test report: https://bit.ly/2xVXh4X

I want to work for the vaping community full time! If you feel what I do is worth a couple dollars a month and you would like early access to battery availability and testing news and a say in what I test then please consider becoming a patron and supporting my testing efforts: https://www.patreon.com/batterymooch

These tests only note the estimated ratings for these batteries at the time I tested them. Any battery that is not a genuine Samsung, Sony, LG, Panasonic, or Sanyo can change at any time! This is one of the hazards of using “rewrapped” batteries or batteries from other manufacturers so carefully research any battery you are considering using before purchasing.

Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage. They are not meant to be used outside of a protected battery pack. Never exceed the battery’s continuous current rating and keep the plastic wrap and top insulating ring in perfect condition.

Any rating in my ratings tables can change at any time as different grade cells appear on the market, we get swamped with fakes, or new information becomes available to me. Please, never assume that the ratings in the tables are permanent and will never change! Always download the latest version before considering any cell purchase.

To see how other cells have tested check out this link: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/

Reactions: Like 4 | Winner 1 | Informative 3


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## M.Adhir

Thanks for the insight.

So these batteries should work well in a 21700 regulated device?
Mirage 75c, Armour Pro - both run single coil atty's between 0.35 and 0.5 ohms.

Reactions: Like 2 | Thanks 1


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## Silver

Thanks @Christos 
This looks like a great battery indeed!

Reactions: Like 1 | Thanks 1


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## Christos

M.Adhir said:


> Thanks for the insight.
> 
> So these batteries should work well in a 21700 regulated device?
> Mirage 75c, Armour Pro - both run single coil atty's between 0.35 and 0.5 ohms.


I can confirm they fit perfectly in an armor mod with about a mm to spare on the sides.
Just tested it in my wife's mod.

Reactions: Like 1 | Thanks 1


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## StompieZA

Great Information! I still need to get a set for the X217!


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## Christos

M.Adhir said:


> Thanks for the insight.
> 
> So these batteries should work well in a 21700 regulated device?
> Mirage 75c, Armour Pro - both run single coil atty's between 0.35 and 0.5 ohms.


Yes, to answer your question properly, I use them in 2 squonkers with a bomber pro mosfet so a regulated device would be perfect.
The 30Ts have a higher amp rating and are recommended for mechs but the hit off the 30T is phenomenal (I hear).
I can feel a noticeable difference in the hit with the 40T vs an 18650 and the ijoy 20700s.

The ijoys I use 2 batts to do 11ml, 18650 lg chocs or Sony vtc5a I use 3 batts but the 40T does 11ml effortlessly.

Reactions: Informative 2


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## Asterix

Christos said:


> Yes, to answer your question properly, I use them in 2 squonkers with a bomber pro mosfet so a regulated device would be perfect.
> The 30Ts have a higher amp rating and are recommended for mechs but the hit off the 30T is phenomenal (I hear).
> I can feel a noticeable difference in the hit with the 40T vs an 18650 and the ijoy 20700s.
> 
> The ijoys I use 2 batts to do 11ml, 18650 lg chocs or Sony vtc5a I use 3 batts but the 40T does 11ml effortlessly.


Thanks for this and the information above. I nearly bought Ijoy 21700’s for my mirages, but will go find some 40T’s instead.

Reactions: Like 2


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## M.Adhir

Christos said:


> Yes, to answer your question properly, I use them in 2 squonkers with a bomber pro mosfet so a regulated device would be perfect.
> The 30Ts have a higher amp rating and are recommended for mechs but the hit off the 30T is phenomenal (I hear).
> I can feel a noticeable difference in the hit with the 40T vs an 18650 and the ijoy 20700s.
> 
> The ijoys I use 2 batts to do 11ml, 18650 lg chocs or Sony vtc5a I use 3 batts but the 40T does 11ml effortlessly.


Thanks man, i will need to find some and order.
Currently get 3 to 4 tanks off the dvarw (so around 10 to 12ml) using ijoy 21700, voltage drops to around 3.5 by that stage.
Will grab a few of these 40T a try them out.

Reactions: Like 2


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## RainstormZA

StompieZA said:


> Great Information! I still need to get a set for the X217!


Same here! Wow I've forgotten about this mod since I got the Alpha Zip mod. Lol. 

I dislike the AVB batteries as I've noticed a power drop as soon as it goes below halfway of use.


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## StompieZA

RainstormZA said:


> Same here! Wow I've forgotten about this mod since I got the Alpha Zip mod. Lol.
> 
> I dislike the AVB batteries as I've noticed a power drop as soon as it goes below halfway of use.



Yeah i also forgot i even had the X217 packed away...Benched the DRAG2 tuesday for a bit and been using the X217 again. A set of 18650s lasts around a day at 65watt, with 21700 i will probably see 2 or 3 days i guess! So i need to make a plan!


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## RainstormZA

StompieZA said:


> Yeah i also forgot i even had the X217 packed away...Benched the DRAG2 tuesday for a bit and been using the X217 again. A set of 18650s lasts around a day at 65watt, with 21700 i will probably see 2 or 3 days i guess! So i need to make a plan!


Get a Gear rta, you'll notice it uses way less power and your batteries last much longer. Two days on dual 18650 batteries, 3 days on the X217 with dual 21700 batteries.


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## StompieZA

RainstormZA said:


> Get a Gear rta, you'll notice it uses way less power and your batteries last much longer. Two days on dual 18650 batteries, 3 days on the X217 with dual 21700 batteries.



Yeah cause its single coil. Ive been looking at some that go up for sale here. Will chat on PM, dont want to derail this thread.

Reactions: Agree 1


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## MrGSmokeFree

Awesome batteries I use them in my Armour Pro and you can get them at the vape shop for R 199 bucks.

Reactions: Like 2


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## BumbleBee

The 40T is an awesome cell, I have 4 of them running in a HOG4 parallel/series mech, so far I've done 60mls of juice and will probably do another 30ml before they need charging.

Reactions: Like 3 | Winner 3


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## Silver

BumbleBee said:


> The 40T is an awesome cell, I have 4 of them running in a HOG4 parallel/series mech, so far I've done 60mls of juice and will probably do another 30ml before they need charging.



That's amazing @BumbleBee !
Wow

Reactions: Like 1 | Agree 1


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## Asterix

Should I be worried....... I received these two today. The code under the wrap, when looked at with a bright light, seems good but I am concerned about the ring on the negative.

Reactions: Like 1


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## Dela Rey Steyn

Those rings are traditionally venting disks. If I may ask, where did you buy them? Pm if you don't want to mention the shop's name on the forum

Reactions: Like 1


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## Puff the Magic Dragon

Take a look at the discussion here. It may help.

Reactions: Like 1


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## Dela Rey Steyn

So the one with the ring is a rewrap according to that article and not a geniune 40T

Reactions: Like 1


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## Asterix

Thanks guys! I saw that link and sent it on to to the local shop. He's waiting for an answer from his international supplier, as they are apparently certified re-sellers (whether that actually means anything).

Reactions: Like 4


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## Shahin

Asterix said:


> Thanks guys! I saw that link and sent it on to to the local shop. He's waiting for an answer from his international supplier, as they are apparently certified re-sellers (whether that actually means anything).



Hi. I know this is an old thread, but I recently bought a 40t that also has the ring on the negative terminal. 

Please do tell, what was the conclusion of your investigation?

Reactions: Like 1


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