# Batteries

Electric cars are powered by batteries that have a huge amount of energy - up to 20,000 AA batteries! Batteries come in all different shapes and sizes, and we use them all the time in our electronic devices, like flashlights and phones. They provide electricity, but what are they really made of and how do they work? This article has all the answers you need about batteries!

## Definition of batteries

To understand what batteries are, we first need to understand what an electrical cell is.

### Electrical cells

An electrical cell stores chemical energy in various ways that aren't important to know to understand how it works. The important thing to know is that a chemical reaction inside the cell creates a difference in electric potential (also known as voltage) between two points of the battery, called poles. The positive pole repels positive charges, while the negative pole isn't the positive pole.

Voltage or potential difference is the amount of energy a unit charge gains when moving between two points. If one particle has twice the charge of another, it will be affected twice as much by the potential difference of a cell, experiencing twice the force. This means that it gains twice the energy as the other particle when traveling from pole to pole. However, the energy gained divided by the charge is the same for both particles, and this is a property of the cell called voltage or potential difference.

### Batteries

A battery is a collection of two or more cells that are connected in series. Each cell has positive and negative pole, and when connected correctly, the potential difference of the battery is the sum of the potential differences of each individual cell. This means that if the cells are connected with the negative end of one cell connected to the positive end of another, the potential differences will add up. So, a battery is essentially a system of multiple cells working together to provide a higher potential difference than a single cell could.

### How do batteries work?

When a particle with a positive charge is placed near the positive pole of a battery, the voltage of the battery causes it to be pushed towards the negative pole. This movement of the particle involves the battery doing work on the particle, as it is exerting a force over a distance. As a result, the battery loses some of its energy, which is derived from the chemical energy stored inside it. In other words, the battery converts its chemical energy into work to move the particle. After this process, the battery contains less chemical energy than before.

The percentage of battery displayed on your phone is a measure of how much chemical energy is remaining inside the battery of your phone. The more you use your phone, the more work it requires, as charged particles need to be moved around to operate the various functions of your phone. This means that more chemical energy from the battery must be converted into work, resulting in the battery depleting faster. Therefore, if you use your phone heavily, the battery will not last as long as it would if you used it sparingly.

## Properties of batteries

The chemical composition and design of a battery determine its capacity to store chemical energy, which in turn determines the amount of electrical energy the battery can provide. The potential difference or voltage between the poles of the battery is also determined by its chemical composition. Voltage determines the amount of energy a unit charge gains when travelling through the voltage difference. The work done on a charged particle is given by the product of the charge and voltage.

A battery with a higher voltage will apply a greater force on a charge than a battery with a lower voltage will apply on the same charge. The capacity of a battery refers to the total charge it can displace from one pole to the other, which is typically measured in coulombs or ampere-hours. The total chemical energy of a battery is the total amount of work it can do, assuming 100% efficiency for simplicity. Therefore, the total charge that a battery can displace from one pole to the other is an important factor in determining its energy capacity.

In summary, the properties of batteries such as battery capacity, voltage, and energy capacity are largely dependent on their chemical composition and design.

## Battery symbol in physics

In physics and electrical engineering, there exist symbols for every element in an electrical circuit, and cells and batteries are no exception. See the figure below for the symbols for an electrical cell and a battery.

We see that the symbol for a battery is a graphical representation of what a battery is, namely a couple of electrical cells joined in series.

## Functions and examples of batteries

Batteries are widely used in a variety of electrical devices, ranging from small devices like phones and digital watches to larger ones like laptops and cars. The primary function of a battery is to provide electrical energy to a system. However, the purpose of this energy can vary depending on the device in which the battery is being used.

In the case of phones, watches, and laptops, the energy from the battery is mainly used to operate the system and power the screen. In cars, the battery is used to power the starter motor, headlights, indicators, and other electrical components. In electric vehicles, the battery is used to power the electric motors that the vehicle forward.

In summary, batteries are essential components of many electrical devices, and their primary function is to provide electrical energy to power the various functions of the device.

## Types of batteries

Another common type of battery is the lead-acid battery, which is commonly used in cars, motorcycles, and other vehicles. These batteries work by converting the chemical energy stored in lead plates into electrical energy. They are known for their reliability and low cost.

A third common type of battery is the alkaline battery, which is often used in household items like flashlights and remote controls. These batteries use an alkaline electrolyte to generate electrical energy from the chemical energy stored inside the battery.

In summary, the three most common types of batteries are lithium-ion batteries, lead-acid batteries, and alkaline batteries. Each of these batteries works differently, but they all convert chemical energy into electrical energy to power a wide range of devices.

That's correct! Nickel-cadmium batteries are indeed rechargeable and are commonly used in power tools and other portable electronic devices. Alkaline batteries, on the other hand, are not rechargeable and are often used in low-drain devices like remote controls and clocks. The chemical reactions that power these batteries are different, but the end result is the same: the conversion of chemical energy into electrical energy to power a variety of devices.

Batteries - Key takeaways An electrical cell is an object that holds chemical energy. There is a potential difference, or a voltage, between its two poles. A battery is a system of two or more cells that are joined in series. The potential difference of a battery is the sum of the potential differences of the individual cells inside the battery. A battery converts its chemical energy into work done on charged particles through the potential difference it creates. Batteries have properties such as battery capacity, voltage, and energy capacity. Battery capacity has units of charge, and it is equal to the energy capacity divided by the voltage. In general,. The symbol for a battery is a schematic drawing of a couple of cells that are joined in series. The function of a battery is to provide electrical energy to a system. There are different types of batteries, which we distinguish by looking at their chemical composition and how they transfer chemical energy into electrical energy.

## Batteries

What is a battery?

The most basic way to view a battery is as a system of two or more electrical cells that are joined in series.

How do batteries work?

Batteries contain chemical energy, which causes a voltage between its poles. This voltage can push charged particles over some distance, which is how the chemical energy is transferred into useful work.

Which energy is stored in a battery?

Chemical energy is stored inside a battery. Different types of batteries use different types of chemical energy.

What are the properties of batteries?

A battery has properties like voltage (in V), battery capacity (in C or Ah), and energy capacity (in J or Wh).

What are the 3 types of batteries?

There are more than 3 types of batteries, but common battery types are lithium-ion, nickel-cadmium, and alkaline.

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