D battery

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A carbon-zinc D battery, positive terminal up.
D cell batteries, wooden matchstick for scale.

A D battery (D cell or IEC R20) is a standardized size of a dry cell. A D cell is cylindrical with an electrical contact at each end; the positive end has a nub or bump. D cells are typically used in high current drain applications, such as in large flashlights, radio receivers, and transmitters, and other devices that require an extended running time. A D cell may be either rechargeable or non-rechargeable. Its terminal voltage and capacity depend upon its cell chemistry.

The National Carbon Company introduced the first D cell in 1898. Before smaller cells became more common, D cells were widely known as flashlight batteries. The U.S. military designation for this battery has been BA-30 since sometime before World War II.[1] During World War II, it was designated the Type C battery by the U.S. Navy, leading to confusion with the smaller C cell battery (BA-42).

In 2007, D batteries accounted for 8% of alkaline primary battery sales (numerically) in the US. In 2008, Swiss purchases of D batteries amounted to 3.4% of primary and 1.4% of secondary (rechargeable) sales.[2][3]

D, C, AA, AAA, AAAA and 9-Volt batteries

Dimensions and capacity[edit]

  Zinc–carbon Alkaline Li-FeS2 NiCd NiMH Li-SOCl2
IEC name R20 LR20 FR20 KR20 HR20 ER?[citation needed]
ANSI/NEDA name 13D 13A 13LF 13K[citation needed] 13H[citation needed]  
Typical capacity milliamphours 8,000 mAh 12,000–18,000 mAh 2,000–5,500 mAh 2,200–12,000 mAh 19,000 mAh
energy 12 Wh 18–27 Wh 2.5–6.9 Wh 2.75–15 Wh 68.4 Wh[citation needed]
Nominal voltage 1.5 V 1.5 V 1.5 V 1.25 V 1.25 V 3.6 V
Rechargeable No Special type only No Yes Yes No



Name / Type of this battery Alkaline Zinc–carbon Li-FeS2 Li-SOCl2 NiCd NiMH
IEC name LR20 R20 FR20 ER?[citation needed] KR20 HR20
ANSI/NEDA name 13A 13D 13LF   13K[citation needed] 13H[citation needed]


Battery capacity and size[edit]

A battery's capacity depends upon its cell chemistry and current draw. Duracell brand rates its alkaline D cell performance as approximately 20,000 mAh at 25 mA draw, but about 10,000 mAh at 500 mA draw.[4] This effect is generally less pronounced in cells with NiMH chemistry and hardly at all with NiCd. Many commonly available size D rechargeable cells are actually sub-C cells in a D-sized holder.

D batteries have nominal diameter of 33.2 ± 1 millimeters (1.3 inches). The overall length is 61.5 millimeters (2.42 inches).[5]

See also[edit]


  1. ^ "U.S. Army Flashlight".
  2. ^ Life Cycle Impacts of Alkaline Batteries with a Focus on End-of-Life - EPBA-EU Archived 7 October 2011 at the Wayback Machine
  3. ^ "Absatzzahlen 2008" (PDF). Archived from the original (PDF) on 25 March 2012. Retrieved 25 March 2012. INOBAT 2008 statistics.
  4. ^ "MN1300 Size: D (LR20) Alkaline-Manganese Dioxide Battery" (PDF). Archived from the original (PDF) on 21 May 2012.
  5. ^ IEC 60086-2 §7.1.4

External links[edit]