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

21700 vs. C Battery

Comparing 2 standards across 4 specifications. 4 key differences identified.

Comparing:
21700
C Battery
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 →
C Battery →

A C battery (IEC designation LR14, ANSI 14A) measures 26.2mm in diameter and 50.0mm in length. Alkaline C cells output 1.5V nominal, with typical capacity in the range of roughly 6,000 to 8,000 mAh -- well above AA or AAA but less common in modern consumer electronics.

View full C Battery spec sheet →

Specification Comparison Table

4 Parameters
Parameter / Spec
21700
C Battery
Diameter
21.10 mm 26.20 mm
Overall Length
70.40 mm 50.00 mm
Nominal Capacity
4000–5000 mAh —
Alkaline Voltage
— 1.50 V

Other Alternatives to Compare

Compare 21700 vs. 14500 → Compare 21700 vs. 18650 → Compare 21700 vs. 26650 → Compare 21700 vs. 9V Battery → Compare 21700 vs. AA Battery → Compare 21700 vs. AAA Battery → Compare 21700 vs. AAAA → Compare 21700 vs. D Battery → Compare 21700 vs. N / LR1 →