These tests below only note the ESTIMATED ratings for these batteries 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 is 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 personal injury or property damage. Use of these batteries is AT YOUR OWN RISK. They are not meant to be used outside of a protected battery pack. Never exceed the battery’s current rating and keep the plastic wrap and top insulating ring in perfect condition.
Testing batteries at their limits is dangerous and should never, ever, 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.
Bottom Line
This is a good performing cell that is slightly overrated. It appears to be the same cell that was used for the Golisi S35 and Efest 35A 3700mAh 21700’s when I tested them. This Eizfan runs a little hotter though so I have given it a 25A rating. Since they all might use the same cell the Golisi and Efest will need to be retested to see if they are also 25A now.
The capacity for the four Eizfan cells was 3857mAh to 4093mAh. China manufactured cells typically have worse cell-to-cell consistency, versus those from Samsung, Sony, etc., but this is a wider capacity range than I usually see. All of the cells I tested easily met their 3750mAh rating though.
Four cells were donated for the purposes of testing by Efan (Shenzhen Yi Fang Technology Co., Ltd. - IMR Battery, Li-Ion Battery). Thank you!
Continuous Current Discharge Graphs
Ratings Graphic
Performance Specs
DC Internal Resistance = 15.8mOhms (milliohms) average for two cells.
Total energy delivered down to 3.2V at 10A continuous = 11.1Wh
Total energy delivered down to 3.2V at 20A continuous = 9.2Wh
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: Battery Mooch is creating battery tests and educating vapers | Patreon.
Efan paid a fee to be moved to the front of the testing queue, which currently has a 10-12 week backlog. This cannot influence my test results as this is science, resulting in hard data, not a subjective review. In addition, they pay in advance, have no say about what is in this report, and I don’t care if any company never does this or donates batteries again. My reputation is a lot more important than any battery donation or fee to be moved to the front of the queue.
To see how other cells have tested check out this link: List of Battery Tests | E-Cigarette Forum
Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage. Use of these batteries is AT YOUR OWN RISK. They are not meant to be used outside of a protected battery pack. Never exceed the battery’s current rating and keep the plastic wrap and top insulating ring in perfect condition.
Testing batteries at their limits is dangerous and should never, ever, 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.
Bottom Line
This is a good performing cell that is slightly overrated. It appears to be the same cell that was used for the Golisi S35 and Efest 35A 3700mAh 21700’s when I tested them. This Eizfan runs a little hotter though so I have given it a 25A rating. Since they all might use the same cell the Golisi and Efest will need to be retested to see if they are also 25A now.
The capacity for the four Eizfan cells was 3857mAh to 4093mAh. China manufactured cells typically have worse cell-to-cell consistency, versus those from Samsung, Sony, etc., but this is a wider capacity range than I usually see. All of the cells I tested easily met their 3750mAh rating though.
Four cells were donated for the purposes of testing by Efan (Shenzhen Yi Fang Technology Co., Ltd. - IMR Battery, Li-Ion Battery). Thank you!
Continuous Current Discharge Graphs
Ratings Graphic
Performance Specs
DC Internal Resistance = 15.8mOhms (milliohms) average for two cells.
Total energy delivered down to 3.2V at 10A continuous = 11.1Wh
Total energy delivered down to 3.2V at 20A continuous = 9.2Wh
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: Battery Mooch is creating battery tests and educating vapers | Patreon.
Efan paid a fee to be moved to the front of the testing queue, which currently has a 10-12 week backlog. This cannot influence my test results as this is science, resulting in hard data, not a subjective review. In addition, they pay in advance, have no say about what is in this report, and I don’t care if any company never does this or donates batteries again. My reputation is a lot more important than any battery donation or fee to be moved to the front of the queue.
To see how other cells have tested check out this link: List of Battery Tests | E-Cigarette Forum
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