Lithium Vs. Alkaline Batteries: What's The Difference?

In a world full of electronics, batteries have become an indispensable part of our day-to-day lives. From fitness trackers like Fitbit to wireless game controllers, we need batteries to power our devices. New devices often come with batteries, saving us from immediately having to put much thought into what would be the best choice. However, as soon as the battery drains and it's time to replace it, choosing a new one can be an exercise in frustration, given the sheer number of options available. As you shop for new batteries for your devices, you'll most often come across two types — lithium and alkaline. 

While on the surface, they might look pretty similar, inside, they're worlds apart. Lithium and alkaline batteries differ in the materials used to make them and their design. That's why they perform differently depending on how you use them. If you need a versatile battery for everyday electronics, alkaline batteries are a good choice since they last longer than other battery types and are relatively inexpensive. On the other hand, if you need to power smart devices or high-tech gadgets, lithium batteries will typically be the better choice.

For the most part, alkaline batteries are designed to be disposable, which is why they're made with inexpensive materials. As one would expect, the result is the price of alkaline batteries is much lower than that of lithium batteries. On Amazon.com, an 8-pack of Energizer Max AA batteries costs $6.99, while an 8-pack of Energizer Ultimate Lithium AA batteries is priced at $22.79. While you'll pay as much as five times more upfront for lithium batteries, they'll last you a lot longer than alkaline batteries, by some estimates as much as six to ten times longer, depending on how you use them.

Given their disposability and low cost, you'll usually see people using alkaline batteries in devices that don't need a lot of power, like TV remotes and wall clocks. However, lithium batteries are generally a better choice for high-drain devices, like headsets and gaming remotes because they have a longer lifespan, and you won't have to replace them as often. 

When you start getting into the nitty-gritty of the differences between lithium and alkaline batteries, one of the first things you notice is that their chemical composition and voltage outputs are different depending on the type of lithium battery. These differences, as well as the battery brand you choose, have a big impact on their performance and how well they work with different devices.

Alkaline batteries have three internal components: an anode (zinc), a cathode (manganese dioxide), and an alkaline electrolyte like potassium hydroxide. The zinc helps the battery generate power while the manganese dioxide completes the reaction, with an alkaline solution (usually potassium hydroxide) allowing the charge to flow. This composition results in a standard voltage of 1.5 volts per cell, which is enough for devices like toys, clocks, remotes, portable lights, and fire detectors. 

There are two main types of lithium batteries: Lithium-metal batteries, which are typically non-rechargeable and lithium-ion batteries, which are rechargeable. You'll find lithium-metal batteries in devices that need power over a long period, such as cameras, while lithium-ion batteries are often used in smartphones and laptops. Just like alkaline batteries, lithium batteries have three main components: An anode (graphite), a cathode (such as cobalt oxide), and an electrolyte (lithium solution) that allows the charge to flow.

Besides the different chemical compositions of the two battery types, lithium batteries have a higher energy density and voltage than alkaline batteries, ranging from 1.5 volts (for lithium iron disulfide) to 3.7 volts (for lithium-ion). That extra power means lithium batteries are a good choice for high-drain devices like digital cameras, smartphones, and other portable electronics. Lithium batteries have a consistent voltage output, meaning they provide a steady performance over time and don't lose voltage like alkaline batteries.

There's no getting around it: All batteries degrade over time, even when you're not using them. However, as we all know, some last longer than others. You might wonder if expensive batteries are really better than cheap ones and if that plays a role in how much life you get out of a battery before having to replace it. 

When we talk about a battery's shelf life, we're referring to how long you can store it before it begins to lose its ability to hold a charge effectively. While batteries don't have an expiration date written on them like a carton of milk, you can get an idea of their shelf life based on how they're stored and their chemical composition. How you store your batteries can have a big impact on their self-discharge rate. High temperatures will cause them to self-discharge more rapidly than if they're stored in a cool, dry place.

Your average alkaline battery typically lasts between seven to 10 years, with a self-discharge rate of approximately 2-3% per year. You can expect a non-rechargeable lithium battery to last anywhere from 10-15 years with little self-discharge, while rechargeable lithium-ion batteries have a shelf life of two to three years, with a self-discharge rate of 5% in the first 24 hours and 1-2% per month thereafter. 

When it comes to standing up to extreme temperatures, lithium and alkaline batteries are not created equal. Temperature can negatively impact both lithium and alkaline batteries, with alkaline batteries performing their best when the temperature is between 0°F and 130°F. It's important to note that even within this recommended range, the battery's performance can vary. At lower temperatures, the chemical reactions inside an alkaline battery slow down, reducing its capacity and efficiency.

While extreme temperatures also hurt the performance of lithium batteries, it's nowhere near as dramatic as what's seen in alkaline batteries. Lithium batteries perform reliably over a wider range of temperatures. On the colder side, the optimal temperature range for lithium batteries starts at around 14°F, but they can still work at lower temperatures. In contrast, when temperatures drop below 32°F, alkaline battery voltage takes a big hit.

Heat negatively affects both alkaline and lithium batteries, with lithium performing slightly better. Most smartphones use lithium-ion or lithium-polymer batteries. When alkaline batteries are exposed to extreme heat on a regular basis, they may leak. If the temperature changes suddenly, alkaline batteries may stop working as well. Lithium batteries are better able to withstand sudden temperature shifts and supply reliable power throughout.

Lithium batteries weigh a lot less than alkaline batteries. A standard alkaline battery weighs about 23 grams, while a standard AA lithium battery weighs approximately 15 grams. Alkaline batteries weigh more because of their chemical composition and construction. While you may not think the weight difference is much, it becomes noticeable when using devices that require more than one battery. That's especially true for portable devices, where added weight can make them uncomfortable to carry around for extended periods of time.

There's no metal lighter than lithium on the periodic table, which is why lithium batteries win in the weight category, making them the most popular choice for lightweight, portable electronics. Their high energy density allows them to store a lot of power relative to their size. That's why you'll often find them in portable devices like handheld gaming consoles, cameras, and cordless power tools, where their light weight ensures they don't weigh down these devices.