D battery

A D battery or D cell is a type of electrochemical cell, the largest in the D, C, AA, and AAA families. Each D cell is cylindrical with electrical contacts at each end; the positive end having a nub or bump. D cells are typically used in high current drain applications, such as in large flashlights, radio receivers and transmitters, portable entertainment systems, products with motors, safety systems or other applications requiring extended run time. Rechargeable and non rechargeable versions are available. Non rechargeable cells are known as primary cells.

Voltage: 1.5 volts
Capacity (Heavy Duty): 8,000 mAh
Capacity (Alkaline): 12,000 mAh

The D cell was standardized by ANSI as "13A" (alkaline) and is known internationally as LR20 (alkaline). The 13D is based on carbon-zinc chemistry, the 13D is marketed as a Heavy Duty cell. The standard D cell has a length of 60.5±1.0 mm (2.38±0.04 in) and a diameter of 33.1±1.0 mm (1.31±0.04 in).

Introduction[edit]

A Duracell D battery in a battery holder.

D sized batteries are dry cells, composed of a single chamber or can be packed with an electrolyte paste and electrode rod that may be either the positive terminal, as on non-alkaline carbon zinc based cells or the negative terminal as in the alkaline based cells. D Batteries are more correctly referred to as D cells. The nominal output voltage of single-use D cells is 1.5 volts, while NiCd and NiMH rechargeable cells have a nominal voltage of 1.2 V. Specialty cells based on more exotic chemistries can operate at voltages as high as 1.6 V under load. The terminal voltage of a D cell is the same as an AAA, AA or C cell, however, they generally can supply current longer, i.e. they store more energy, than C, AA or AAA cells although rechargeable AAs can run longer than disposable D cells (even with less nominal voltage).

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 type since before WW II is BA-30.[1]

Capacity[edit]

4.5-Volt, D, C, AA, AAA, 9-Volt, SR41/AG3, SR44/AG13 cells

Because of their larger size, which allows them to store a greater mass of anode material (an electrode that is consumed as it supplies electrical current), the D sized battery can supply power for a longer time than C, AA or AAA cells at equal current levels.

In some cases, rechargeable D batteries have significantly less capacity (as low as 1,800 mAh) than the primary or single use non-rechargeable type because they are internally only an AA or C cell. Many, however, are made as true D cells with greater capacities than their alkaline counterparts and any C or AA battery.

Battery type	Typical capacity in mAh
AA	2,400
C	7,800
D	12,000

Non-standard D cells[edit]

There are some batteries on the market that are labelled as "D"-size, and are shaped as "D"-size, but which are different.

Some of these are rechargeable "D"s are sealed lead-acid cells with a nominal voltage of 2 volts (the voltage of a single lead-acid cell). These may have a capacity of 5000 mAh. ^[1]

References[edit]

Citations[edit]

↑ BatteriesPlus Australia; Hawker 0810-0004 (D Cell)