These tests below only note my personal opinion for the 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, EVE, Lishen, BAK, 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
I tested these “engineering samples” in February, 2024 for my Patreon supporters. Now that these are becoming available for retail purchase I’m posting some of my test results. Results of cycle-life testing beyond 300 cycles (comparing it to the P45B), my EXTREMELY high current testing, and other tests will remain patron-only.
The Molicel P50B is an extraordinary cell and runs for longer than the P45B by a couple percent at up to about 20A. At 30A the P50B runs for about 5% longer and at 40A it runs for 12% longer.
This makes it the best performing round cell I’ve tested for moderate to extremely high power applications. I have yet to to test the EVE 40PL and Ampace JP40, cells with very high current ratings, but will be directly comparing them to the Molicel P45B and P50B.
For discharging at low power levels, about 7A and lower, the Samsung 50S, BAK N21700CG-50, and LG M50LT will all run for a bit longer than the P50B. But as the power levels keep rising the P50B gets better and better.
After 300 abusive cycles (30A discharge to 2.5V, recharge at 5A while still warm) the P50B only lost about 11.5% of its run time and had essentially the same max temperature and DC internal resistance as when new. This is incredible.
Some other general information…
Teardown
Continuous Current Discharge Graphs
Ratings and Performance Specs Graphic
18650 Ratings and E-Scores Table:
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20700/21700 Ratings and E-Scores Table:
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I want to work for the 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, battery testing and news, and a say in what I test, then please consider becoming a patron and supporting my testing efforts: Get more from Battery Mooch on Patreon.
To see how other cells have tested check out this link: Links To All 21700, 26650, 18350, 18500 Battery Tests
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
I tested these “engineering samples” in February, 2024 for my Patreon supporters. Now that these are becoming available for retail purchase I’m posting some of my test results. Results of cycle-life testing beyond 300 cycles (comparing it to the P45B), my EXTREMELY high current testing, and other tests will remain patron-only.
The Molicel P50B is an extraordinary cell and runs for longer than the P45B by a couple percent at up to about 20A. At 30A the P50B runs for about 5% longer and at 40A it runs for 12% longer.
This makes it the best performing round cell I’ve tested for moderate to extremely high power applications. I have yet to to test the EVE 40PL and Ampace JP40, cells with very high current ratings, but will be directly comparing them to the Molicel P45B and P50B.
For discharging at low power levels, about 7A and lower, the Samsung 50S, BAK N21700CG-50, and LG M50LT will all run for a bit longer than the P50B. But as the power levels keep rising the P50B gets better and better.
After 300 abusive cycles (30A discharge to 2.5V, recharge at 5A while still warm) the P50B only lost about 11.5% of its run time and had essentially the same max temperature and DC internal resistance as when new. This is incredible.
Some other general information…
- The datasheet lists a 60A “maximum continuous discharging current” rating but that’s temperature-limited to 80°C and is not a continuous current rating down to the 2.5V cutoff. This is typical for Molicels though since they are targeting products that don’t run the cells continuously.
- The datasheet also mentions “cycle life is reduced at high rates” and this is to be expected. These are incredibly high currently levels.
- Since this cell reaches 80°C when run continuously at about 35A I’ll be giving it an estimated 35A continuous/60A temp-limited rating.
- This cell showed no signs of stress at 60A, initially dropping down to about 3.55V and smoothly discharging from there until it reached the 80°C limit (where I stopped the discharge).
- The datasheet lists a 25A “maximum continuous charging current” rating but also says that high rate charging will quickly reduce cycle life.
- Discharging can be done at a cell surface temperature of -40°C to 80°C in ambient temps of -40°C to 60°C. When below -20°C though you must raise the low voltage cutoff but the datasheet does not say to what level. I recommend staying above 3.0V until we know more. There’s almost no capacity below that anyway when cold.
- Charging can be done at a cell temp of -20°C to 70°C in ambient temps of -20°C to 60°C. This is the first cell that I’ve seen that can be charged when the cell is below 0°C.
- This is not a “tabless” cell, see teardown below. It does have additional internal tabs though to better handle the higher current levels.
- I had cells from two batches, Sept 2023 cells delivered 4992mAh and 5013mAh and had 9.52mOhms and 9.52mOhms DC IR.
- The Nov 2023 cells delivered 4976mAh and 4977mAh and had 9.30mOhms and 9.46mOhms DC IR. This is above its 4850mAh minimum capacity rating and close enough to its 5000mAh typically rating that I will be rating them at 5000mAh. These are engineering samples (so capacity could increase a bit for production) and equipment differences can easily lead to slightly different capacity measurements.
- The largest of the four cells was 21.3mm in diameter and 70.2mm long.
- I do not know if the P50B’s available on Alibaba/AliExpress are samples or production cells. The last I heard these weren’t going into full production until the end of the year so I suspect the available ones are still samples but I do not know for sure.
Teardown
Continuous Current Discharge Graphs
Ratings and Performance Specs Graphic
18650 Ratings and E-Scores Table:
18650 Battery Ratings and Performance 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:
21700 Battery Ratings and Performance 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
I want to work for the 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, battery testing and news, and a say in what I test, then please consider becoming a patron and supporting my testing efforts: Get more from Battery Mooch on Patreon.
To see how other cells have tested check out this link: Links To All 21700, 26650, 18350, 18500 Battery Tests
