D Battery | Size, Weight & Applications (2024)

An electric battery is essentially a source of DC electrical energy. It converts stored chemical energy into electrical energy through an electrochemical process. This then provides a source of electromotive force to enable currents to flow in electric and electronic circuits. A typical battery consists of one or more voltaic cells.

The fundamental principle in an electrochemical cell is spontaneous redox reactions in two electrodes separated by an electrolyte, which is a substance that is ionic conductive and electrically insulated.

A D battery, also known as an R20 battery, is one of many types of single-cell cylindrical batteries. D batteries are large batteries, that are typically used in medium-to-high drain applications such as large toys,flashlights, and musical instruments. They have significantly higher capacity than AA and even C batteries.

Dimensions and Weight of D Battery

D batteries have a nominal diameter of 33.2 millimeters (1.3 inches). The overall length is 61.5 millimeters (2.42 inches). Its weight ranges from160-180 grams.

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. This effect is generally less pronounced in cells with NiMH chemistry and hardly at all with NiCd batteries. Many commonly available size D rechargeable cells are actually sub-C cells in a D-sized holder.

Types of D Batteries

D batteries are basically divided into primary and secondary. Several different chemistries are used in their construction. The exact terminal voltage, capacity, and practical discharge rates depend on cell chemistry; however, devices designed for D cells will usually only take 1.2-1.5 V unless specified by the manufacturer.

Primary C Battery. A primary battery or primary cell is a non-rechargeable battery that is designed to be used once discarded after use. These batteries are most commonly used in portable devices with low current drains, are used only intermittently, or are used well away from an alternative power source, such as in alarm and communication circuits where other electric power is only intermittently available. Primary cells have higher energy density than the rechargeable secondary cell, but most types of primary cells have high inner impedance and will therefore cause a big voltage drop during high discharge current, limiting the power capacity.

• Alkaline battery. An alkaline battery (IEC code: L) is a type of primary battery that provides direct electric current from the electrochemical reaction between zinc and manganese dioxide (MnO₂) in the presence of an alkaline electrolyte. The alkaline battery gets its name because it has an alkaline electrolyte of potassium hydroxide (KOH) instead of the acidic ammonium chloride (NH₄Cl) or zinc chloride (ZnCl₂) electrolyte of the zinc–carbon batteries. The alkaline cell was introduced to the market in 1959 but did not become more common than the Zinc-carbon cell until around 1980.
• Lithium metal battery. Lithium-based primary cellsare batteries that have metallic lithium as an anode. They have the lowest self-discharge rate hence the longest available shelf time, up to 10 years, and in temperatures up to 70. Using an iron disulfide cathode gives a battery with a nominal voltage of 1.5 volts. This cell is used for high-performance AA batteries.
• Zinc-carbon battery. The zinc-carbon battery, also called the Leclanché cell, is a traditional general-purpose dry cell. Zinc–carbon batteries were the first commercial dry batteries developed from the technology of the wet Leclanché cell. This battery provides a direct electric current from the electrochemical reaction between zinc and manganese dioxide (MnO₂) in the presence of an electrolyte. It produces a voltage of about 1.5 volts between the zinc anode, which is typically constructed as a cylindrical container for the battery cell, and a carbon rod surrounded by the cathode that collects the current from the manganese dioxide electrode. The name “zinc-carbon” is slightly misleading as it implies that carbon is acting as the reducing agent rather than the manganese dioxide.
• Zinc-chloride battery. The zinc-chloride battery is a type of primary battery developed from a zinc-carbon cell. It is frequently referred to as a heavy-duty, extra-heavy-duty, super-heavy-duty, or super-extra-heavy-duty battery. Zinc-chloride cell is an improvement on the original zinc-carbon cell, using purer chemicals and giving a longer service life and steadier voltage output as it is used and offering about twice the service life of general-purpose zinc-carbon cells, or up to four times in continuous-use or high-drain applications.

Secondary C Battery. Secondary batteries, also known as secondary cells, or rechargeable batteries, are batteries that can be recharged by driving electric current in the opposite direction of the discharge current. Rechargeable batteries are often more expensive, but in high-drain applications, they offer greater value as they can be reused. In low-drain applications, the service life is more important, and the self-discharge characteristics of a rechargeable battery mean that they are less suitable for use as the primary energy source.

• NiMH battery. A nickel-metal hydride battery, NiMH, is a secondary battery with a positive electrode made of nickel hydroxide and a negative electrode made of a metal hydride (a hydrogen-absorbing alloy). The NiMH battery was commercially introduced in 1989 and was mainly used as a power source in portable personal computers. Since then, the NiMH battery system has become very popular in electric hybrid vehicles and makes up 10% of the total market for rechargeable batteries. Compared to the NiCd battery, the NiMH provides 40 percent higher specific energy resulting in about two times higher capacity. NiMH batteries are also less affected by the memory effect.
• NiCd battery. The nickel-cadmium battery (Ni-Cd battery) is a type of secondary battery using nickel oxide hydroxide Ni(O)(OH) as a cathode and metallic cadmium as an anode. The abbreviation Ni-Cd is derived from the chemical symbols of nickel (Ni) and cadmium (Cd). The battery has low internal impedance resulting in high power capabilities but lower energy storage capacity compared to other battery systems. It has long cycle life and capability of rapid recharge but may suffer from voltage depression or memory effect

Characteristics of D Batteries

To compare and understand the capability of each battery, some important parameters are characteristic of each battery, also within a type of battery. These parameters are a reference when a battery is needed, and specific qualities are required since batteries are used in all types of devices and for infinite purposes.

Other Types of Batteries

The following list summarizes notable electric battery types composed of one or more electrochemical cells. Four lists are provided in the table. The first list is a battery classification by size and format. Then, the primary (non-rechargeable) and secondary (rechargeable) cell lists are lists of battery chemistry. The third list is a list of battery applications. The final list is a list of different battery voltages.