C Battery vs. D Battery
Comparing 2 standards across 3 specifications. 2 key differences identified.
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.
A D battery (IEC designation LR20, ANSI 13A) measures 34.2mm in diameter and 61.5mm in length -- the largest common cylindrical primary cell. Alkaline D cells output 1.5V nominal, with typical capacity in the range of roughly 12,000 to 20,000 mAh depending on discharge rate.