Batteries Explained: How Batteries Work

Your favorite gadget loses power and you need a new battery. Luckily, some people know their D cell from their button cell batteries. But many of us would struggle when asked if we want a lithium cell or a dry-cell alkaline AA battery. 

Italian physicist Alessandro Volta couldn’t have foreseen how his accidental discovery of the battery in 1800 would shape the world. Or how his surname would become volt, the international unit for measuring the force of an electric current. 

We’re still addicted to batteries more than two centuries after Volta’s enlightenment. Cars, cell phones, and pacemakers all use batteries. Astonishingly, we throw away an estimated 15 billion batteries globally every year. 

These life-enhancing power sources are worthy of understanding. So, let’s look at different types of batteries, how they work, how we make them, and their limitations. 

How Do Batteries Work?

Batteries store energy, giving us access to portable electricity. Stored energy is also called potential energy. As such, a charged idle battery is full of stored chemical energy, or electrical energy, within a battery cell. 

Activating the battery converts that stored energy into an electric current. We call this energy kinetic energy because it is the energy of movement. Electricity is movement between atoms, with electrons banging into each other, creating an electrical flow. 

What Does Battery Voltage Mean?

The higher a battery’s voltage, the more electric current it can produce. You can’t start a car with a double-A battery; you need a larger 12-volt battery. 

You’ll also see mAh values on batteries. This mAh value, or milliampere hours, relates to the battery’s storage capabilities. As a rule of thumb, the higher a battery’s mAh value, the more energy it can store, the longer it takes to recharge, and the longer its power will last. 

Are Batteries AC or DC?

Batteries are direct current (DC) power. That means they offer a steady and controllable energy flow to a circuit. 

What Happens Within a Battery Cell to Create Electricity?

Let’s look at a classic AA battery. The Duracell Coppertop AA battery is an instantly recognizable brand used in toys, remote controls, and more. 

Batteries have a negative end called an anode and a positive end called a cathode. Between the positive and negative ends is the battery’s body, full of electrolytes. Put together, this is an electrochemical cell. A battery usually has several of these cells. 

First, we must complete the electrical circuit. Then, a chemical reaction happens when we turn on our battery-powered electrical gadget.  

Now, the negative anode reacts with the electrolytes in the battery’s body. This produces electrons which build up at the anode. Batteries usually use materials that are good at giving up their electrons for this process, called oxidation. 

At the battery’s positive end, the cathode also reacts with the electrolytes in the battery’s body. Something different happens here; the cathode creates ions, which are atoms with too few electrons. Cathodes are usually made from metal oxides that want to gain electrons and ions. 

Now we have electrons that want to travel from the negative anode to the positive cathode. But our body’s battery, the electrolytes, stops that from happening. The electrons are trapped. But thanks to our electrical circuit, the electrons have another option. 

The wires in our gadgets are excellent electricity conductors. They will gladly let these electrons travel along them from the anode to the cathode. Electricity is the movement of electrons, which is why a battery-operated flashlight turns on or a remote control works. It benefits from the electrical current generated by the electrons flowing through the wires from the battery’s negative anode to the positive cathode. 

The electrolytes in non-rechargeable batteries have a limit to the number of times they can perform this chemical reaction. That’s why batteries run flat. Scientists call any electron exchange reaction a reduction-oxidation or a redox reaction. 

What’s Inside a Battery?

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Let’s look inside a classic Energizer Max AA alkaline battery with a steel body and PVC covering as a label. Here are the standard components of what is an electrochemical cell with various seals and washers: 

Anode: Powdered zinc gel 

Cathode: Manganese dioxide or graphite gel 

Electrolytes: Soluble salts or acids in dry or gel formats, such as sodium, chloride, or potassium hydroxide 

Separator: A brass rod that collects current and stops short circuits within the battery 

What Are the Two Types of Battery Cells?

Two types of electrochemical cells are found in batteries: voltaic, also known as galvanic, and electrolytic. 

A voltaic cell’s energy comes from the above-mentioned reactions, a reduction-oxidation or redox reaction. The battery’s energy storage turns into electrical energy when activated. 

Electrolytic cells draw energy from external sources like a charger and turn that electrical energy into stored chemical energy. A cell phone is an electrolytic cell while charging. Unhook it and use it in the street. That battery uses its energy storage, operating as a voltaic cell. 

This also shows us one of the main differences in batteries. There are rechargeable and non-rechargeable batteries. Non-rechargeable batteries are called primary or single-use batteries. 

What Are the Different Battery Sizes?

Assuming they’re made from the same materials, the bigger the battery, the more powerful it is. That’s because the extra storage space allows more electrolyte storage. 

The following batteries are usually cylindrical or have a rounded, rectangular shape. They can be single-use or rechargeable. 

• AAAA batteries: 1.5 voltage, slim, trim, and offers high power discharges and long shelf life. 
• AAA batteries: Slightly larger than the AAAA batteries, these slim, triple-A batteries are common in low-power gadgets like TV remotes, offering 1.5 voltage. 
• AA batteries: Double-A batteries also offer 1.5 voltage and are the most common batteries most people see. They are larger than AA and AAA batteries. 
• A23 batteries: These cylindrical batteries are 12 voltage and common in-home security Bluetooth devices. 
• C batteries: Back to 1.5 voltage but better adapted to higher-energy appliances like flashlights. 
• D batteries: Also known as D cells, these cylindrical 1.5 voltage batteries suit high-drain devices like digital cameras or large flashlights. 
• 9V batteries: These rectangular 9-volt batteries are perfect for higher-demand appliances like smoke detectors. 
• CR123A batteries: This cylindrical battery is 3 volts, known as the camera battery. Its small size delivers a relatively large amount of power to energy-hungry electronic appliances. 
• CR2032 batteries: Button cell batteries are smaller than the traditional batteries mentioned above. The CR2032, which is found in watches, delivers 3 volts with a high weight-to-power ratio. 
• Lithium coin cell batteries: These are the lithium-ion version of the button cell battery. 

What Are the Different Types of Batteries?

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Primary, or non-rechargeable batteries, are not just throwaway batteries. A pacemaker is a primary, or dry-cell, battery. Battery life spans often depend on their materials, particularly in the anode and cathode. This has led to a proliferation of battery types. 

Zinc Carbon Batteries

Zinc carbon batteries have zinc and carbon electrodes, common in low-energy devices like TV remotes. These are often the free “batteries included” that come with some purchases and run out quickly. Those with zinc chloride have greater potential energy and may be labeled as heavy-duty batteries. 

Alkaline Batteries

Alkaline batteries have zinc anodes but manganese dioxide cathodes. This gives them long-lasting performance compared to zinc carbon batteries. Alkaline batteries also perform better in cold conditions and have a longer shelf life. Most standard AA, AAA, C, D, and 9-volt batteries are alkaline. 

Lithium Batteries

Lithium batteries use a lithium anode, hence the name, and an iron sulfide cathode. Lithium batteries are non-rechargeable. 

Lithium-ion Batteries

Lithium-ion batteries power our cell phones and other portable electronic equipment and are rechargeable. They have a lithium-carbon compound anode and a cathode made from lithium-metal oxides. Lithium-ion batteries power electric cars and store excess renewable energy at giant battery farms. 

Lead-Acid Batteries

Lead-acid batteries are famous as car batteries but are also used in wheelchairs and photovoltaic solar energy systems. Features include their heavy weight, rechargeability, long life, and cheap manufacturing costs. Lead-acid batteries have lead anodes and lead dioxide cathodes; their electrolytes are sulfuric acid. 

Nickel-Cadmium or NiCad Batteries

These rechargeable batteries, sometimes abbreviated to Ni-Cd or NiCAd batteries, drive our power tools. The anode is metallic cadmium, and the cathode is nickel oxide hydroxide. They are tricky to recycle and often need recharging even when the battery isn’t empty. 

Nickel Metal Hydride, or NiMH Batteries

Replacing a Ni-CD’s cadmium anode with a lanthanide or nickel alloy birthed the NiMH battery. The NiMH battery has superior recharging properties and is safer than their Ni-CD cousins. NiHm batteries may be in video game controllers and digital cameras. 

Finally, button batteries are common in watches and pagers and look like little buttons. They also have a zinc anode but pair with a silver oxide cathode. Button cell batteries generally have a long life. Zinc-air button batteries extend that lifetime further by combining a zinc anode with an oxygen cathode, typically seen in hearing aids. 

Are Batteries Recyclable?

Yes, batteries are recyclable. Batteries should never be thrown into the regular trash because they contain dangerous and toxic materials like mercury, lead, and cobalt. This is especially important for lithium batteries, according to the United States Environmental Protection Agency. 

Alkaline and zinc carbon batteries should be sent to a specialized battery recycler. Ask your local waste authority for pick-up points for Ni-CD, NiZn, and NiMH batteries, be they rechargeable or non-rechargeable. 

Never put button-cell, coin, or lithium single-use batteries in the trash or recycling bins. Contact a specialist recycler or the hazardous waste department. Take lead or electric car batteries back to a battery retailer or the carmaker and never dispose of them in regular waste. Battery recycling is vital if we want to protect the environment. 

Are Batteries Capacitors?

Batteries and capacitors are similar yet different. 

They can both store potential electric energy, called voltage, creating an electric current that can power appliances. 

However, a battery can store much more energy than a capacitor in its chemical field, releases that energy in a steady stream, and loses its charge-holding capacity over its lifetime. 

Conversely, a capacitor stores energy in an electric field and provides rapid bursts of energy. Capacitors are rechargeable, unlike all batteries, and their nontoxic components are more straightforward to discard than those of a battery. 

What Problems Does Using Batteries Cause?

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Batteries are not a perfect power source; they run down, require recharging, and utilize energy-heavy manufacturing techniques to create. 

For example, water is kryptonite to a battery; it can rust the battery, draining its power, stopping it from working, and possibly making it explode. It’s best not to use batteries once they’ve gotten wet. 

Will Batteries Work in Freezing Weather? 

Yes, most batteries will work in freezing weather. Of course, batteries can freeze and not work if the temperature drops significantly. For example, a car’s lead-acid battery works at around half its room temperature efficiency once the thermometer drops below freezing. 

• Don’t charge any frozen battery. 
• Charge lead-acid batteries at room temperature when possible, or between -4 and 122 degrees Fahrenheit. 
• Charge lithium-ion batteries between 32 and 113 degrees Fahrenheit. They should work between -4 and 140 Fahrenheit. 
• Alkaline batteries function between -4 and 149 degrees Fahrenheit. Only charge alkaline batteries between 32 and 113 Fahrenheit. 

If in doubt, do not charge or use a battery and seek professional advice. 

Can I Take Batteries on a Plane?

People watch films on their laptops or play games on their cell phones while flying, all using battery power. So yes, you can take most batteries on a plane—but not all.  

Always check with your airline which batteries can travel with you in the hold or have to go with checked baggage. 

Batteries allowed in carry-on bags include: 

• Dry cell alkaline batteries, the familiar triple-A, double-A, C, D cell, 9-volt, and button types 
• Dry cell rechargeable batteries (NiMH and NiCad) 
• Lithium-ion batteries in most cell phones, laptops, and cameras 
• Lithium metal batteries in cameras and most personal electronic devices 

Spare lithium batteries may not be packed into your checked bags. Some airlines also have restrictions on battery sizes. It’s good practice to take permitted batteries into the cabin with you. 

Prohibited batteries include car batteries, wet batteries, and spare lithium batteries. 

Can Batteries Explode?

Although infrequent, batteries certainly can explode and catch fire. Defective batteries may short circuit, producing heat, fire, or an explosion. 

When Were Batteries Invented?

Alessandro Volta was an Italian physicist who invented the battery. In 1800, Volta constructed his cell with a zinc anode and a copper cathode. His electrolyte solution was humble salt and water. 

He discovered a difference in the electric potential between a cathode and anode. The measurement of this difference was named after him: the volt. 

How Do You Use Batteries Now and in the Future?

Count how many battery-operated devices you use at work and home; you might be surprised. Our energy-driven world depends not just on electricity, oil, gas, and nuclear power. Batteries help us access energy in convenient and remote places alike. 

Lithium-ion batteries power our cell phones and are driving the electric vehicle revolution. Renewable energy is increasing but needs batteries to capture any excess electricity generated during sunny spells or windy storms, so we maximize green energy’s benefits. 

Imagine there is a power outage. With no battery planning, the flashlight doesn’t work. Clearly, battery storage is important, as is recycling the precious materials used to make them. 

A chemical reaction sends electrons on a journey from the negative to the positive ends of a battery, giving us portable electricity. We, too, must grasp the favorable possibilities of batteries to maximize our future power sources. 

Brought to you by energysavings.com

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