Side-by-Side Comparison
Cylindrical Cells
21700 vs. AAAA
Comparing 2 standards across 6 specifications. 6 key differences identified.
Comparing:
21700
AAAA
A 21700 Li-ion cell measures 21.1mm in diameter and 70.4mm in length. Offering 4000 to 5000 mAh capacity at 3.6V nominal, it provides up to 50% more energy density than an 18650 cell.
A AAAA battery (IEC designation LR8D425) is a 1.5V Alkaline cell measuring approximately 8.3mm in diameter and 42.5mm in length -- smaller than a AAA. It's used in devices with especially tight internal space, such as laser pointers, some styluses, and compact LED penlights.