Side-by-side comparison of Samsung INR21700-40T (21700) and Sanyo NCR18650GA (18650)
| Samsung INR21700-40T | Sanyo NCR18650GA | |
|---|---|---|
| Capacity | 4000 mAh | 3500 mAh |
| Nom. Voltage | 3.6 V | 3.6 V |
| Max Current | 35 A | 15 A |
| Weight | 70 g | 48 g |
| Energy | 14.4 Wh | 12.6 Wh |
| Energy Density | 206 Wh/kg | 263 Wh/kg |
| Form Factor | 21700 | 18650 |
| Typical R_int | 19.8 mOhm | 42.0 mOhm |
Showing 10A discharge rate for both cells
| Current | Samsung INR21700-40T | Sanyo NCR18650GA |
|---|---|---|
| 0.2A | — | 42.0 |
| 0.5A | — | 42.0 |
| 0.8A | 19.8 | — |
| 1.0A | — | 55.5 |
| 2.0A | — | 57.8 |
| 3.0A | — | 53.5 |
| 4.0A | 17.1 | — |
| 5.0A | — | 47.1 |
| 7.0A | — | 43.4 |
| 10.0A | 17.1 | 39.2 |
| 15.0A | — | 34.3 |
| 20.0A | 16.6 | — |
| 35.0A | 16.2 | — |
Values in mΩ. Bold = lowest resistance at that current.
The Samsung 40T offers 14% more capacity (4000 vs 3500 mAh). The Samsung 40T supports higher continuous discharge (35A vs 15A), making it better for high-drain applications. The Panasonic NCR18650GA has better energy density (263 vs 206 Wh/kg). The Panasonic NCR18650GA is lighter at 48g. Note: these are different form factors (21700 vs 18650), so direct substitution is not possible without pack redesign.