A Quick Primer on Battery Types

  When it comes to powering a project, we often have to choose between using batteries to increase the mobility of a device or exploring other options, such as simple 5V USB power supplies, to power our project. Many beginners are hesitant to add batteries to a project due to the increase in cost, the need for additional safety features, and missing experience. This blog should serve as an entry point to working with different batteries, as it discusses some of the most common types and what you have to look out for when working with specific batteries!

Primary Versus Secondary Batteries

The easiest way to categorize a battery is by determining whether you can recharge it or not. Non-rechargeable batteries are also called primary batteries, and they are typically cheap, readily available, maintenance-free, and safe to store for prolonged periods. Besides, they are easy to work with and relatively secure. The most popular primary battery is the Alkaline battery, but other types, such as Carbon-Zinc, are also available. Typically, primary batteries are employed in devices that draw low currents over a prolonged period.

Secondary batteries, on the other hand, are rechargeable, and they can deliver much higher currents over a short period. These batteries have become omnipresent in our modern lives, as they typically power devices such as power tools, mobile phones, and other consumer electronics. The downside of such batteries is that they are generally more expensive than primary batteries. Furthermore, secondary batteries often also require more elaborate safety mechanisms to prevent catastrophic failures.

Popular Primary Battery Types and their Properties

Alkaline batteries are the most commonly found type of primary battery. They are easy to find, and they are relatively cheap. Besides that, Alkaline batteries have a long shelf life of typically multiple years due to their low self-discharge. This makes them perfect for buying in bulk and storing them until you need them. As mentioned, Alkaline batteries are typically used in applications that draw little current over prolonged periods. However, while it’s possible to power modest loads with this type of battery, doing so will deplete them rather quickly because of their high internal resistance.

Lithium-Iron-Disulfide batteries are a modern replacement for Alkaline batteries. They overcome some of the problems of Alkaline batteries, for example, the high internal resistance. These batteries, however, are also harder to find and typically more expensive than Alkaline batteries.

Popular Secondary Battery Types

Many people know lead-acid batteries as they are commonly used in vehicles. These secondary batteries are typically cheaper than other types of rechargeable batteries. They, however, also have many downsides. These batteries don’t tolerate deep discharges too well, and it can take up to several hours to recharge one. Lead-acid batteries are often also large and heavy. These points make them practically useless in small mobile applications. They are, however, useful in vehicles and as backup batteries in uninterruptible power supplies.

Another secondary battery is the Nickel-Cadmium (NiCd) battery, which you can commonly find in many battery-powered tools. NiCd batteries can deliver a very high current output, and they are typically fast and easy to recharge. On the downside, these batteries have a high level of self-discharge, which is even higher when the battery is fully charged. NiCd batteries are also highly toxic, which is one reason Nickel-metal-hydride (NiMH) batteries are a good alternative. NiMH batteries have the same properties as NiCd batteries, but they are less toxic.

Li-Ion batteries are another essential group of secondary batteries, and they come in many different types, named after their active materials. Today, consumers can often find Li-Ion batteries in various applications ranging from consumer electronics to power tools and electric vehicles. These small and light batteries can deliver very high output currents. However, one downside of Li-Ion batteries is their high price and the need for protection circuitry that prevents the cells from being charged too much or getting deeply discharged.

Summary

The easiest way to categorize a battery is by determining if you can recharge it. Primary batteries are non-rechargeable, while secondary batteries can get recharged. Primary batteries are typically used in applications that require little power over a long period, as they have a good shelf-life and a high internal resistance. Typically, primary batteries are also cheap, readily available, and easy to use. Secondary batteries, on the other hand, can often deliver much higher currents. That’s one reason why engineers often employ them in applications that require high current in short bursts. Rechargeable batteries are typically more expensive and not as easy to work with. Furthermore, many types of secondary batteries, such as Li-Ion, require protection to ensure safe operation and to prevent catastrophic failures.