# item.guide
Side-by-Side Comparison Cylindrical Cells

14500 vs. 21700

Comparing 2 standards across 5 specifications. 5 key differences identified.

Comparing:
14500
21700
14500 →

A 14500 Li-ion cell measures 14mm in diameter and 50mm in length -- the same physical size as a standard AA battery -- but delivers 3.7V nominal rather than an AA's 1.5V. Because it fits mechanically into AA-sized battery holders, mixing it up with a real AA can destroy 1.5V-only circuitry.

View full 14500 spec sheet →
21700 →

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.

View full 21700 spec sheet →

Specification Comparison Table

5 Parameters
Parameter / Spec
14500
21700
Diameter
14.00 mm 21.10 mm
Overall Length
50.00 mm 70.40 mm
Nominal Operating Voltage
3.70 V —
Chemistry
Lithium-ion —
Nominal Capacity
— 4000–5000 mAh

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