These tests below only note my personal ESTIMATED ratings for the batteries I tested at the time I tested them. Any battery that is not a genuine Samsung, Sony, Murata, LG, Panasonic, Molicel, or Sanyo can change at any time! This can be one of the hazards of using “rewrapped” 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 property damage, personal injury, or even death. Never use them outside of a fully protected battery pack and you use them at your own risk. Never exceed the battery’s true continuous discharge rating (CDR), never let it get colder than 0°C or hotter than 60°C, and keep the plastic wrap and top insulating ring in perfect condition. Never use a battery that is physically damaged in any way.
Testing batteries at their limits is dangerous and should never be attempted by anyone who has not thoroughly studied the dangers involved, understands the risks, has the proper equipment, and takes all appropriate safety precautions.
If the battery has only one current rating number, or if it only says "max", then I have to assume the battery is rated at that current level for any type of discharge, including continuous.
Test Results
It’s been over four years since I last tested this cell so I thought it was worth seeing if the performance has changed. This is the third version of the 20S, identified by a “3” in the lower left corner of the printing on the wrap.
The 20S3’s I tested performed about the same at 10A and 20A as the ones I tested in 2018. They did not perform as well at 30A though, running for about 20% less time.
Even though I recently purchased these cells I believe their data code shows they were made in 2018. This could be the reason for the drop in performance at high discharge rates compared to the 20S3’s I tested last time. I’m wondering if Samsung 20S cells are still being manufactured.
These are still the hardest hitting 18650’s you can buy for the first few hundred mAh. After that other cells like the Molicel P28A will hit harder since they hold up their voltage for longer due to their higher capacity.
Two 20S3 cells tested out to 2009mAh and 2016mAh, which is fantastic consistency and is typical for Samsung. Both exceeded their 2000mAh rating but only by a little. Samsung cells usually have an actual capacity well above their rating. A loss of some capacity is typical of cells that are left in storage for a long time though so I would not expect the cells I tested to have the same capacity as recently made cells. I have not tested the cycle life of these cells.
18650 Ratings and E-Scores Table:
You are responsible for your own safety! These batteries are designed, manufactured, and sold only for use in a battery pack with the proper protection circuitry and battery management system. They were not designed for vaping (electronic...
www.e-cigarette-forum.com
20700/21700 Ratings and E-Scores Table:
You are responsible for your own safety! These batteries are designed, manufactured, and sold only for use in a battery pack with the proper protection circuitry and battery management system. They were not designed for vaping (electronic...
www.e-cigarette-forum.com
Continuous Current Discharge Graphs
Ratings and Performance Specs Graphic
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List of Battery Tests