D Batteries

While they may be less common than other dry cell batteries (such as AA or AAA batteries), D batteries can be particularly useful when it comes to powering larger devices that may require a lot of energy, or that need to be relied upon over long periods of time without the necessity of regularly changing the batteries. Here are some common circumstances where D batteries may be indispensable.

Size and composition of D batteries

A D battery is a cylindrical dry cell battery with a diameter of 33.2mm and a length of 61.5mm. While the dimensions remain unchanged, D batteries may be composed of different materials, including zinc-carbon, alkaline, lithium, NiCd, and NiMH. They are larger than other single cell batteries such as C, AA, and AAA batteries, and are subsequently capable of delivering a higher current. The overall life of a D battery will depend on the power drain of the device it is placed in, however it is also worth noting that any battery will also eventually lose its power over a lengthy period without use.

Devices that use D batteries

Given their large size and capacity for energy storage, D batteries are typically best-suited for large electronic devices, in particular those that draw a high current. For this reason they are commonly found in products such as large flashlights, radio receivers, and electronic transmitters.

Their large capacity also means they are likely to last longer without use prior to losing their charge, which makes them ideal for items that may not be used every day, but that may be needed urgently in the case of an emergency. Again, this makes them particularly useful in devices such as flashlights and radios.

Disposable D batteries vs. rechargeable D batteries

D batteries may be found in both disposable as well as rechargeable formats. Disposable D batteries are single use, and need to be safely disposed of and replaced once their charge is depleted. The initial investment on disposable D batteries is typically lower than that of rechargeable D batteries, and they also tend to hold their charge longer when not in use in comparison to rechargeable AAA batteries.

On the other hand, the energy stored in rechargeable D batteries can be replenished many times over their lifespan. Rechargeable D batteries regularly cost more (including the up-front investment of a charging device), however over time the cost is generally offset after a few instances of recharging. Of course if a rechargeable D battery runs out of power, you may have to wait for the battery to recharge if you do not have a replacement or spare on hand.