Samsung INR21700 40T
This is a fantastic performing cell that easily beats the Sanyo NCR20700A at both high and low discharge current levels. At moderate power levels this Samsung 40T even beats the incredible Samsung 30T, hitting harder for almost the entire discharge down to 3.2V and for a lot longer too.
At high power levels though the lower internal resistance of the Samsung 30T allows it to hit harder than the Samsung 40T for most of the discharge down to 3.2V (about 3.6V resting voltage). The 40T still runs for longer though.
This is a classic tradeoff, the 30T’s higher performance and current rating versus the 40T’s higher capacity. The 40T still performs better than the Sanyo NCR20700A and would be an amazing cell for high power regulated vaping. Even for mech’s if the 30T wasn’t available.
This cell delivered 3962mAh and 3985mAh in my capacity tests. Judging by Samsung’s “40T” designation for it I am sure its nominal/typical capacity rating will be 4000mAh. However, its guaranteed/minimum rating is always lower than the typical/nominal rating and will probably be 3800mAh or 3900mAh.
I am giving this cell an estimated continuous rating of 25A or higher and a minimum capacity rating of about 3900mAh. I will give firm ratings when I get the production cells next year.
- Brand: Samsung
- Model: 40T
- Size: 21700
- Nominal Capacity: 4000mAh
- Nominal Voltage: 3.6V
- Maximum Voltage: 4.2V
- Discharge Current: 30A Maximum Continuous
- Style: Flat Top
- Protected: NO, UNPROTECTED
- Approximate Dimensions: 21.1mm x 70.4mm
- Approximate Weight: 66.8g