Here, we will talk about the basics of D Battery, along with its important parameters and specifications. We will also take a look at the typical set of applications of D Cells or Batteries. We will also explore different types of D Batteries i.e., different chemistries, primary (non-rechargeable), and secondary (rechargeable).
What is a D Cell Battery?
If you fall into the millennial, Gen-X, or boomer demographic, then chances are you are familiar with D Batteries as flashlight batteries. This is because we used them extensively to power those long flashlights that took two (or sometimes three) of these batteries. But what exactly is a D Battery? A D Battery is a type of cylindrical battery, where the ‘D’ indicates the physical size of the battery similar to AA or AAA (if you remember, AA and AAA also represent the size of the batteries). A D Battery is a slightly longer and wider version of an AA or AAA battery. Another similarity between a D Battery and AA or AAA batteries is they all have only one cell, which is the main electrochemical unit. Hence, we often call the D Battery the D Cell. While The American Ever Ready Company introduced AA and AAA batteries in 1907 and 1911 respectively, the National Carbon Company introduced the D Battery (or D Cell) much earlier in 1898. Even after the introduction of more minor AA and AAA batteries, D Cells were very popular for a long time, especially for flashlights. Even the U.S Military used these batteries in radio transceivers during World War II. We will give more details about the D Cell Battery in the next section.
Specifications Of D Cell Batteries
In the previous section, we mentioned that the D Battery is a bigger version of the AA battery. But what is the actual size of a D battery? What are the other important specifications of a typical D Cell? Let us explore more about these aspects of a D Cell Battery.
1. Size
The first and most important specification of a D Battery is its physical size. If you take the height or length of a D Battery, the minimum height is 59.5 mm while the maximum height is 61.5 mm. Coming to the diameter of the D Battery Cylinder must be a minimum of 32.2 mm and a maximum of 34.2 mm. Apart from these two dimensions, we also have dimensions of the positive and negative terminals. We know that the positive terminal in most cylindrical batteries has a protrusion. This is also the case with a D Battery. The height of the positive terminal must be at least 1.5 mm while the diameter of the positive terminal must be less than or equal to 9.5 mm. Next, we have the negative terminal. In addition to the flat negative terminal, as we find in AA and AAA batteries, some D Batteries also come with recessed negative terminals. Irrespective of the type of the negative terminal, its diameter must be at least 18 mm. The data sheet of the battery or manufacturer’s description will specify the negative terminal contact i.e., flat or recessed.
2. Voltage
Despite the large size of a D Battery when compared to AA and AAA batteries, the typical voltage of a D Battery is still 1.5V. Of course, this voltage is only for non-rechargeable primary type D Batteries. Does this mean we get rechargeable secondary D Batteries? The answer is yes, we do. Again, the similarity between rechargeable D Batteries and rechargeable AA or AAA batteries continues. The typical voltage of a rechargeable D Battery is around 1.2V. We will see more details on rechargeable and non-rechargeable D Cell Batteries in a later section.
3. Capacity
The advantage of a large-size cell such as a D Cell is it can have ridiculously large energy ratings. If you remember, an alkaline AA battery can have a maximum capacity of around 3,000 mAh. Coming to a D Battery with similar chemical composition i.e., an Alkaline type battery, you can get them in capacities as high as 20,000 mAh. You read it right. Even regular Zinc Carbon type D Batteries have a huge 8,000 mAh capacity. In contrast, AA batteries of similar type max out at 1,700 to 1,800 mAh.
4. Weight
Continuing the large-size aspect of the D Cell Battery, its typical weight is around 140 grams. If you compare this with an AA Battery, its typical weight is only 23 grams. These weight numbers that we mentioned are for Alkaline type batteries (both D Battery and AA Battery). Depending on the chemical composition of the batteries, their weights can be slightly more or less than these numbers. But you get the idea of the weight of a D Battery compared to an AA Battery.
5. Applications Of D Batteries
The most common and popular application of D Cells is flashlights. Apart from lighting applications, D Batteries are also popular in high-power consumption devices such as radios, portable stereos, toys, etc.
6. Runtime
The runtime of a D Battery depends on the application, its current draw, and how long you use it. We can take some standard numbers and make an estimate of the runtimes for some common applications of D Cell Batteries. For this explanation, we will consider a brand-new Alkaline type D Cell with 1.5V and a typical capacity of 18,000 mAh. Low-intensity lighting system (a flashlight with low-intensity mode) has a current draw of 650 mA. If you take this application, then you can run the light with a D Cell continuously for 27 hours. But if you switch to high-intensity mode, where the current draw increases to 1,000 mA, you can expect the battery to last for almost 18 hours. Another popular application of a D Battery is a portable stereo. As an example, let us assume that it draws about 600 mA of current and you intend to use the stereo for approximately 2 hours a day. If this is the case, then you can expect the battery to last for 12 to 15 days.
Types of D Cells
In the previous section, we covered briefly about types of D Batteries. But in this section, we will explore all the common and popular types of D Cell Batteries you can get. Similar to AA and AAA, you can get D Batteries as both Primary i.e., non-rechargeable and Secondary i.e., rechargeable types. Before moving further, we would like to mention that non-rechargeable type D Cells are way more common than their rechargeable counterparts.
1. Non-Rechargeable D Cells
Let us begin the discussion with Primary type D Batteries. The most common type of D Cell is a Zinc Carbon cell. It consists of Zinc metal as an anode and a mixture of Manganese Dioxide and graphite (carbon) in the form of paste as the cathode. The addition of carbon powder improves the conductivity in the cell. These batteries use Ammonium Chloride (NH4Cl) as an electrolyte. Another popular type of D Battery is the Alkaline type D Cell. While the composition of electrodes is the same as the Zinc Carbon Cell i.e., Zinc metal as anode and Manganese Dioxide as cathode, the difference is in the electrolyte. Alkaline cells use Potassium Hydroxide (KOH) as the electrolyte. The advantage of alkaline cells over regular cells is they are available in much larger capacities and also, they can deliver much higher currents without heating. As both these batteries are non-rechargeable, their voltages are 1.5V. Also, the capacities of these batteries are very high. You can get a Zinc Carbon type D Cell with capacities of up to 8,000 mAh. Coming to the Alkaline type, you can get them with capacities anywhere between 12,000 to 18,000 mAh.
2. Rechargeable D Cells
While rechargeable AA and AAA batteries are very common, it is not the case with D Cells. Yes, you can get rechargeable D Batteries but they are not hugely popular or common. The two common types of rechargeable D Cell Batteries are Nickel Cadmium (NiCd) and Nickel Metal Hydride (NiMH). Yes, this is exactly the same chemical composition as the rechargeable AA and AAA batteries. Remember, the terms AA, AAA, and D refer only to the size of the batteries and have nothing to do with the chemistry, capacity, or any other parameters. Coming back to the rechargeable type D Cells, both Nickel Cadmium and Nickel Metal Hydride batteries use Nickel Oxide Hydroxide as the cathode. But the anodes are different. It is Cadmium metal in Nickel Cadmium batteries while is a metallic alloy in the case of Nickel Metal Hydride batteries. Both these batteries use Potassium Hydroxide as an electrolyte. Also, the voltage of these batteries is around 1.25V. As they are rechargeable batteries, their capacities are slightly less than their non-rechargeable counterparts. For instance, you can get a Nickel Cadmium D Battery with capacities in the range of 2,000 to 5,500 mAh. In the case of the Nickel Metal Hydride type, the capacities are slightly large in the range of 2,500 to 12,000 mAh.
Comparison Of Types Of D Cell Batteries
The following table shows all the important parameters and specifications of the four common types of D Cell Batteries (two from non-rechargeable and two from rechargeable).
Conclusion
While lithium-ion-type batteries are trying to dominate every application, be it large or small, there are some older types of batteries that are still popular. If you take AA and AAA-type batteries, we often use them in remote controls, wall clocks, wireless computer peripherals, etc. Electrolyte – Ammonium Chloride (or Zinc Chloride) Electrolyte – Potassium Hydroxide Electrolyte – Potassium Hydroxide Electrolyte – Potassium Hydroxide Another oldie but Goldie is the D Cell Battery, which is famous as the Flashlight Battery. Apart from flashlights, we also use D Batteries in toys, radios, stereos (portable ones), etc. In this guide, we saw all the essential things about a D Battery or D Cell. We saw its basics, important parameters, and specifications such as physical dimensions, typical capacities, voltage rating, etc. After that, we looked at different types of D Cells i.e., Primary or Non-Rechargeable and Secondary or Rechargeable. We also saw a simple comparison of the different parameters of all four common and popular types of D Cell Batteries. We hope that this guide on D Cell Battery could help you understand everything about the D Battery. If you feel we missed something or want us to add anything, do let us know in the comments section. It will not only help us but other readers as well. Comment * Name * Email * Website
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