A BATTERY MOOCH POST: Samsung 40T 35A 4000mAh 21700…amazing performer but 25A/35A

This is another retest to check on the performance of this cell as it, hopefully, comes into full production soon.

This cell outperforms every 18650 and 20700 in regulated devices at up to about 20A-25A (60W-75W). Only the Samsung 30T hits harder for 21700’s. In my opinion though it is not a 35A battery, as rated in the datasheet.

At 35A continuous this cell reaches almost 90°C. That is too hot to ensure decent cycle life. A rating of 25A continuous brings it to about the same temperature that the Samsung 30T reaches at its rating.

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. The 40T is still an amazing 25A 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. 

The two cells I tested delivered 4048mAh and 4062mAh at 0.8A (0.2C) down to 2.5V.

I am estimating this cell’s ratings to be 25A with a temperature-limited rating of 35A (if kept below 80°C) and 4000mAh.

Two cells were donated for the purposes of testing by Fogstar (http://www.fogstar.co.uk). Thank you!

Ratings graphic: https://imgur.com/a/gtJHCAW

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

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.

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Author: John Muchow