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What are batteries?

Batteries are stores of chemical energy that can be converted to electrical energy and used as a power source.

In this article you can learn about:

  • What batteries are
  • Different types of battery
  • New ideas about storing energy
  • What the advantage and disadvantages of batteries are

This resource is suitable for energy and sustainability topics for primary school learners.

Video - Batteries and energy stores

In this video, learn about different types of batteries and how they work.

Watch this short video to find out about different types of batteries and energy stores.

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Why are batteries useful?

Batteries can be used to power portable devices. They let devices use electricity without the need to be plugged into main electricity sources, such as wall sockets. Mobile phones, tablets, the TV remote and torches all use batteries.

Some batteries are rechargeable so they can be used again and again. Charging them with electricity from renewable sources can help us fight climate change by reducing our need to burn fossil fuels.

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Types of batteries

What are alkaline batteries?

Four alkaline batteries of different sizes
Image caption,
Alkaline batteries power a lot of household items, including remote controls, torches, clocks and toys. They can't be recharged so need to be recycled when they run out of energy. (romiri / Alamy Stock Photo)

Alkaline batteries are the type of battery we use for things like TV remotes, games controllers and torches.

These batteries have a small amount of power and are easy to move around or remove. However, once their energy is used up, they need to be recycled.

Some types of alkaline batteries are rechargeable so they can be reused many times before they need to be recycled.

Four alkaline batteries of different sizes
Image caption,
Alkaline batteries power a lot of household items, including remote controls, torches, clocks and toys. They can't be recharged so need to be recycled when they run out of energy. (romiri / Alamy Stock Photo)

What are lithium-ion batteries?

A lithium ion battery
Image caption,
Lithium batteries can be recharged. You'll find them in portable devices like mobile phones, laptops and electric toothbrushes. (Zoonar GmbH / Alamy Stock Photo)

These power things that need more energy than an alkaline battery, such as computers, mobile phones and electric cars. Once their energy is used, they can simply be recharged.

Lithium batteries are expensive to make and mining the materials needed for them, such as cobalt, causes pollution. These materials are also often in parts of the world with poor worker’s rights and dangerous working conditions, such as the Democratic Republic of Congo.

Lithium-ion batteries can also waste a lot of heat energy when they get hot.

Did you know?

  • When you recharge your phone you are recharging the phone’s lithium-ion battery.
  • Some solar farms use huge lithium batteries to store the electricity captured by solar panels. The batteries can then supply this electricity to the National Grid at night or on cloudy days when the solar panels are not generating any electricity.
A lithium ion battery
Image caption,
Lithium batteries can be recharged. You'll find them in portable devices like mobile phones, laptops and electric toothbrushes. (Zoonar GmbH / Alamy Stock Photo)

What are hydrogen batteries?

A hydrogen battery in a car
Image caption,
Hydrogen batteries can be used to run vehicles. (David Gee / Alamy Stock Photo)

A hydrogen battery is like an engine. It stores which can be combined with oxygen in a chemical reaction that releases energy. Apart from energy this reaction only produces water. There is no pollution and no carbon dioxide or other greenhouse gases are released.

However, lots of the hydrogen is produced by burning fossil fuels. Using hydrogen batteries might not harm the environment, but fueling them can be harmful.

A hydrogen battery in a car
Image caption,
Hydrogen batteries can be used to run vehicles. (David Gee / Alamy Stock Photo)

What are gravity storage batteries?

Gravitricity gravity storage battery in Edinburgh
Image caption,
As our reliance on wind and solar energy grows, we need to develop new storage technologies like the Gravitricity system. This acts like a giant battery to balance and store the electricity coming from renewable sources of energy. (Gravitricity / Peter Dibdin)

Gravity storage is a new method of storing energy, so it works a bit like a battery.

A large block of concrete is placed on a system of pullies up a tower or in a deep hole, like a mine shaft. When more electricity is being generated than is being used, instead of this energy being wasting it can be used to power a winch that pulls the concrete block to the top of the hole.

When more electricity is needed, the concrete block is lowered. This movement turns a turbine which generates electricity.

Gravitricity gravity storage battery in Edinburgh
Image caption,
As our reliance on wind and solar energy grows, we need to develop new storage technologies like the Gravitricity system. This acts like a giant battery to balance and store the electricity coming from renewable sources of energy. (Gravitricity / Peter Dibdin)
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Recycling batteries

Batteries contain harmful chemicals that can leak as the battery rots and cause damage to the environment. This makes it important to recycle batteries if we can.

A leaking battery and a pair of battery recycling containers
Image caption,
Supermarkets often have drop-off containers for alkaline batteries. (Sergio Azenha / Alamy Stock Photo ; Paul Sampson / Alamy Stock Photo)
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The advantages and disadvantages of batteries

Advantages

  • Batteries store energy which means we can reduce waste of energy. This can help us to reduce the amount of non-renewable energy we use and therefore helps the environment.

  • Many batteries are easy to remove and replace or recharge.

  • Many batteries are small and portable, so they can provide electricity for mobile devices and vehicles.

Disadvantages

  • Some batteries are expensive to make or cause pollution in the process of making them.

  • Some batteries such as lithium-ion batteries use materials which are mined in places where worker’s rights and children’s rights might have been abused.

  • Chemicals from old batteries can pollute the ground and water supplies, unless they are recycled.

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Key words about batteries

- Batteries contain chemicals and chemical energy is the energy stored within these chemicals. Energy is released when there is a chemical reaction between these chemicals.

- This is when one or more substances react with each other creating a new substance. When you make a cake or bake bread, chemical reactions take place and a new substance is formed.

- Fossil fuels are fuels that come from the Earth. Fossil fuels are all old life forms that have decomposed and been compressed over a long period of time underground or under the sea. Coal, oil and gas are fossil fuels. Learn more here: What are fossil fuels?

- Hydrogen is a very common gas. It has no smell, taste or colour. It is the most common chemical element in the universe.

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Test your knowledge

Quiz

Challenge

Challenge

Find and make a list of all the battery-operated devices in your house

In the list note whether it has an alkaline battery (one that can be removed, replaced and recycled when its energy is used) or a lithium-ion battery (one that can be recharged).

Make a tally chart of how many there are of each battery type.

Learn more about making tally tables and other charts here: How do I record and display data?

Important! Ask an adult for help in doing this task as some battery-operated devices in your house might be unsafe to handle by yourself.

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