Efest 20700 3100 mAh 30A Imr Batteries
The tests below merely record the approximate ratings for these batteries at the time of my testing. Any battery that is not an authentic Samsung, Sony, Murata, LG, Panasonic, Molicel, or Sanyo carries the risk of unexpected changes. This is particularly true for "rewrapped" batteries or those from different manufacturers. Therefore, it is essential to conduct thorough research on any battery you consider purchasing.
Improper handling or misuse of lithium-ion batteries can pose significant dangers to your safety and property. Using these batteries is entirely at your own risk; they should only be used within a protected battery pack. Never exceed the battery's current rating, and make sure that the plastic wrap and top insulating ring are in perfect condition.
Testing batteries beyond their limits is hazardous and should never be attempted by individuals who have not extensively studied the associated risks, understood the dangers involved, possessed the necessary equipment, and taken all appropriate safety precautions.
If a battery displays only a single current rating or states "max," it should be assumed that this rating applies to all types of discharge, including continuous discharge.
Efest 20700 Mooch In Conclusion
This cell appears identical to and performs virtually the same as some 20700 batteries, a highly efficient cell rated at 30A.
However, the wrap of this cell bears an indistinct and, therefore, meaningless "max" rating of 40Α, like the Efest 18650 3000mAh. Despite my efforts, Efest has not provided any information regarding their "max" ratings, except mentioning the use of pulses lasting a few seconds. No details were given regarding the time intervals between pulses or the criteria for establishing the rating.
The presence of "IMR" on the wrap is incorrect. Efest does not utilize the LMO (lithium-manganese-oxide) battery chemistry associated with the "IMR" model number prefix. Instead, it would use one of the chemistries connected with the "INR" model prefix utilized by Moli.
During testing, the capacity of the four cells ranged from 2874mAh to 2944mAh at a current of 620mA (0.2) down to 2.5V. This is significantly below Efan's rating of 3100mAh.
The Molicel INR20700A carries a minimum capacity rating of 2800mAh and a typical capacity rating of 3000mAh, so it is frustrating to observe Efan's rating of this cell as 3100mAh. Based on my assessment, I am assigning this cell a rating of 30A and 2800mAh.
Performance Specifications
- Average DC Internal Resistance = 19.5mOhms (milliohms) for two cells.
- Total energy delivered down to 3.2V at a continuous current of 10A = 7.7Wh
- Total energy produced down to 3.2V at a constant current of 20A = 6.8Wh
- Total energy produced down to 3.2V at a constant current of 30A = 4.6Wh
Efest paid a fee to expedite their placement in the testing queue, which currently has a backlog of 10-12 weeks. However, this payment does not influence my test results since my approach is rooted in scientific methodology, yielding objective and data-driven conclusions rather than subjective evaluations.
Furthermore, they make the payment in advance, have no influence over the content of this report, and it does not matter to me if any company chooses to refrain from such payments or battery donations in the future. Upholding my reputation holds far greater importance than any battery donation or fee to prioritize testing.