Vapcell K40 21700 4000mAh Battery

Vapcell K40 21700 4000mAh Battery


Availability: 396 in stock

Vapcell K40 21700 4000mAh Battery

Get a FREE VapCell Battery Case with each purchase of 2x K40 batteries!

Mooch’s Battery Review
Bench Test Results: Vapcell Black K40 – 30A 4000mAh 21700…about equal to Samsung 40T
Test Report Summary: This is a good performing cell, about equal to the Samsung 40T down to about 3.1V. Below that voltage the 40T will run for a little longer than the K40. The Molicel P42A performs a little bit better than both the K40 and 40T though. The 45A “max” rating of this Vapcell is useless, ignore it.
This is not a Samsung 40T rewrap! I do not know what cell they are using though and I do not know how this cell’s cycle life (overall life) compares to the Samsung 40T.
This is a long cell, about 70.6mm with about a 21.3mm diameter, and it has a slightly recessed top contact.
It has a slightly recessed top contact.
The two cells I tested delivered 4005mAh and 4007mAh. This is great consistency and I am rating them at 4000mAh.
I would prefer to see these rated at 3900mAh by Vapcell though since the two cells I tested cannot be the lowest rated ones in the batch. The big manufacturers like Samsung, Murata, LG, etc., typically rate their cells a decent amount below the lowest capacity you will measure for any cell. For example, the 3000mAh rated Samsung 30Q typically delivers over 3100mAh.
These cells were donated for testing by Vapcell ( Thank you!
Full Test report:


Model: K40

Size: 21.1*70.6mm

Typical Capacity: 4000mAh (0.2C discharge)

Min capacity: 3900mAh (0.2C discharge)

Nominal voltage: 3.60V

Max Continuous Discharge Current:30A

Max Discharge Current: 45A with 80℃ cut

End-of-charge voltage: 4.20V

End-of-discharge Voltage: 2.5V

Weight: 68g ( Appr)

Internal resistance: 10mΩ ( Appr) (AC 1kHz)

Standard Charge: 2000mA,CCCV 100mA cut-off

Quick Charge Current: 6000mA


Unique Features :

Performance similar as 40T

Weight 0.03 kg
Dimensions 1 × 1 × 10 cm
Availability Now available in-store at
254 Cowper St, Warrawong 2502

Powered With Oliver Pos

Shopping Cart
Scroll to Top