Comparison · Batteries

Vapcell K40 21700 4000mAh 30A/45A or Basen BS217A

Two models side by side: measurements taken by the author in their reviews, and their conclusions. The better value in each row is highlighted.

In brief: Based on review measurements: Capacity: Vapcell K40 21700 4000mAh 30A/45A (4049 mAh vs. 4000).

Model	Vapcell K40 21700 4000mAh 30A/45A2021Read review →	Basen BS217A2020Read review →
Current, A	30	30
Capacity, mAh	4049	4000
Test current, A	30	30
Review conclusion	Recommended	With reservations

Only in one review: Voltage 3.6 V (Vapcell K40 21700 4000mAh 30A/45A); Capacity at high current 3826 mAh (Basen BS217A); Energy 14.71 Wh (Vapcell K40 21700 4000mAh 30A/45A); Temperature rise 90 °C (Vapcell K40 21700 4000mAh 30A/45A).

Vapcell K40 21700 4000mAh 30A/45A: The author identifies it as a rewrapped Samsung INR21700-40T and praises its output and consistency, though the price is a drawback.

Basen BS217A: The cells suit medium loads but noticeably lag high-current competitors at 20 A.

Figures were taken from the review text and checked against the quoted passages. Measurement conditions differ between reviews, so read the reviews yourself before buying. Prices at the time of review.