A D cell battery, also known as a D battery, is a kind of an electrochemical cell. This means that, much like the other AA or AAA batteries you normally use in your flashlights, transmitters, and radio receivers, it comes in the form of a cylindrical chamber consisting of an electrolyte paste and an electrode rod which passes through it.
It will also have electrical contacts positioned at each end. The positive end will have a bump or nub, while the negative end will have a small depression. So now you might be wondering, what then is the difference? What exactly makes the D cell stand out and what are some of the best D cell batteries out there.
D Cell Vs. C And AA Cells: How Much Voltage Do They Have?
If you take a look at your typical AA batteries and C batteries, they are all listed as having 1.5 volts. Well, this is the same with D cells. They have the very same nominal output voltage of 1.5 volts. However, despite this, there is still a difference between the three.
The first and most obvious difference is that D cell batteries are bigger in size. The standard D cell will normally have a length of about 2.38+-0.04 inches (60.5+-1.0 mm) and a diameter of 1.31+-0.04 inches (33.1 +-1.0 mm). This means they won’t just fit into any regular appliance, which raises another question. If they have the same voltage ratings, why not use the smaller AAA batteries on everything and make things smaller and lighter? Well, that is where the second major difference comes in – the battery’s current.
You see, in an electrical device or circuit, there will be two main things. One is voltage, and the other one is current, both of which can be tested using some of the best multimeters. To explain the two more easily, we shall compare them to a water pipe, with water flowing through it. In this case, the voltage will be like the water pressure that pushes the water down the pipe. Current, on the other hand, will be the amount of water that flows down the pipe.
So Where Do D Cells Come In?
So, now that you know the difference between voltage and current, you will find that for some electronics to operate efficiently, they will need more current, but they won’t need more voltage. If your appliance needs a lot of current and you try setting it up with tiny batteries, it will not work as well. This is where the D cell batteries come in. They work by supplying more current to the appliance than your average C cell battery could.
You see, D cells have a larger capacity, which lets them hold a greater mass of the anode material. (This is usually an electrode that consumed inside the battery to supply electrical current). Because D cell batteries store more energy, they are able to supply current for longer than the other cells, even at equal current levels. However, in some cases, rechargeable type AA batteries can run longer when compared to disposable D cells.
D cells also come in rechargeable form. However, sometimes the rechargeable ones will have a significantly lower capacity than the single-use, primary or non-rechargeable type. This is because they are internally actually a C or AA cell. Most of them, however, are true D cells that hold greater capacities that the C or AA batteries. In fact, while AA and C batteries will have a typical capacity of 24,00 and 7,800 mAh respectively, D cell batteries will have as much as 12, 000 mAh.
Need More Voltage?
As for when you need more voltage, you can simply add a couple of batteries together. In most electronics, this would mean that you arrange them such that the positive end of one battery touches the negative end of the other one. This is referred to as adding them in series. Therefore if you add two batteries in the series, each having 1.5 volts, in the end, you will have a total of 3 volts.
However, there is another less common arrangement called parallel. Here, the batteries would be arranged in a straight line, and the negative will join the negative, and the positive will join the positive of the next battery. In this case, if you connect two equal batteries, the voltage will remain the same as that of one battery. So if you are connecting, say 3 D cell batteries, the voltage will still remain 1.5 volts.
It is important to note that you have to be careful only to connect batteries of equal voltage in this type of arrangement. For example, if you connect a 3-volt battery with a 1.5-volt battery in parallel, there will be an argument about which voltage it should be at. You should avoid this at all costs.
Beware of Non-Standard D Cells!
Another thing is you have to be keen on the kind of battery you buy. Some will be labeled as being D sized or take the shape of a D cell battery, but they will be a bit different. Some of them are actually rechargeable D’s, which consist of sealed lead-acid cells and will have a nominal voltage of 2 volts. The capacity of these kinds of cells will usually be a little lower (about 5000 mAh).