These tests only note my personal ESTIMATED ratings for these batteries at the time I tested them. Any battery that is “rewrapped” (not in its original factory wrap) can change at any time! This is one of the hazards of using these batteries 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 to help lower the risks and extend cell life, 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
These appear to be pre-productions samples (no CCC*** logo) and they are fantastic performers…
- For the first part of a discharge they are one of the hardest hitting cells we can buy, especially at extreme power levels. Its incredibly low 5mOhm DC IR is probably helping a lot with that.
- The 40XG performs essentially the same as the EVE40PL, Ampace JP40, and Reliance RS40, check the Ratings & E-Scores tables for the numbers.
- It can’t compete with the best 5000mAh cells over the entire discharge (none of the 4Ah-4.5Ah cells can) but it’s one of the best 4000mAh-4500mAh cells and competes well down to about 3.2V. If discharging below that cells like the RS50, P50B, and 50PL run for longer at any power level.
- Its 45A continuous and 90A temp-limited (to 80°C) current ratings seem reasonable.
- Standard charge rate is 2A and max is 12A. But cycle life will be shortened if you charge any cell quickly. For long cell life I recommend 2A.
- The 40XG has a spiral weld line on the bottom (where the anode of the cell is internally welded to the can) but, thankfully, it’s different from other cells using a spiral. This makes it easier to determine which are being used for rewrapped cells.
***China Compulsory Certification, additional testing now required for all cells made or sold in China after August 1, 2024. The logo and certain information must be put on all cells once they are certified. This typically won’t be done by a manufacturer until the cell is ready to go into full production.
Continuous Current Discharge Graph
Ratings and Performance Specs Graphic
18650/21700 Ratings & E-Scores and Recommended Batteries Tables:
The links are in my public Patreon pinned post:
https://www.patreon.com/posts/pinned-post-137974946
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