This would save you time on having to decide the right battery for the job.

Unfortunately, we do not live in an ideal world where this universal battery exists. The world is filled with many different types of battery that range in size, shape, voltage, current capacity, chemical composition, etc.

The CR2032 is one of the many types of battery available, which is primarily used for smaller electrical and electronic devices. 

Below is a list of devices that CR2032 batteries are used for;

• Car key fobs
• Calculators
• Mini flashlights
• Digital vernier callipers 
• Kitchen scales
• Guitar tuner
• Motherboards (backup)
• Small toys
• Remote controls

There are many more applications where CR2032 batteries are used, and this article shall take a closer look at them. 

Different types of batteries

To better understand the different applications CR2032 batteries are used for, it will first help to learn about the different batteries available.

This will give you a more clear view of why CR2032 batteries are used for these particular applications. 

Key characteristics of batteries

There are a set of characteristics that make each battery unique. The characteristics include;

• Chemical Composition
• Voltage Rating
• Current capacity rating 
• Shape
• Size
• Energy density
• Specific Energy Density 

Chemical composition

Batteries produce electrical power from chemical reactions that occur inside the battery. There are a range of chemicals that are used in different batteries which include;

• Nickel-Cadmium (Ni-Cd)
• Zinc-Carbon 
• Lithium-Ion (Li-Ion)
• Lead-Acid 
• Alkaline 

Voltage Rating

This is one of the main ratings of a battery and refers to the amount of electrical potential a battery holds given in the standard unit of Volts.

All batteries have a theoretical voltage, however, the actual voltage produced will be lower.

This is due to polarisation and resistance losses, and is largely dependent on the current drawn by the load and the internal impedance of the battery. 

Current capacity rating

Current capacity is the next major rating of a battery and relates to the amount of charge (current) that a battery is able to hold.

Depending on the size of the battery, the current capacity can be given in Amp-Hours (Ah), or Milli-Amp-Hours (mAh).

Just like voltage, a battery has a theoretical current capacity that will be higher than its actual measured current capacity.

Shape and Size

While there are many different characteristics, the shape and size of a battery are the characteristics that you can physically distinguish one battery from another.. 

Below is a list of the many different shapes and sizes;

• 9V 
• AA 
• AAA 
• C & D 
• Coin cell
• Button cell
• Flat/Pouch

Energy density

Different sizes and shapes of battery will have different energy densities, which is the energy can derived per unit volume of the weight of the battery.

Specific Energy Density

This is the product of the current capacity and voltage of a battery for one full discharge cycle. It can be derived per unit weight of the battery as well. 

Primary and secondary batteries

All batteries no matter size, shape, voltage, current capacity, etc, can be divided up into two categories; Primary and Secondary.

Primary batteries are batteries that can only be used once. This is why they are often referred to as disposable or single use batteries. 

Once they have fully discharged (and gone flat), you will have to throw them out. 

They cannot be used again.

Secondary batteries on the other hand are rechargeable. This means that when they have fully discharged, you can recharge them (with the help of a battery charger).

How many times a battery can be recharged is dependent on its chemical composition which will determine its lifespan. 

Secondary batteries are a much better option than primary batteries due to the fact that they do not have to be thrown out. 

The disposing of single use primary batteries causes large piles in landfills and is not very environmentally friendly.

The CR battery

CR is a family of batteries consisting of  batteries that resemble a coin, and is why they are termed coin cell batteries.

The CR2032 is a single battery that comes from this family of batteries.

CR batteries might look the same, however they have one distinguishing feature being their physical dimension. 

While they might share the same voltage and shape, they vary in physical size.

Closer look at CR2032 batteries

The letters and numbers of the CR2032 aren’t just picked randomly, but rather are specifically chosen, representing its chemical composition and physical dimension. 

These letters, and numbers are crucial in selecting the right coin cell battery for the job (more so the numbers). 

Let’s take a look at what they mean.

The first letter, ‘C’, represents the chemical composition of the battery. In this case it is made up of Chromium (however, while that was the earlier composition, CR batteries can be made with various different compositions, with Lithium being the most common). 

Next, the letter ‘R’, tells us the shape of the battery, which is round.

The next two numbers in the sequence (in this instance ‘2’ and ‘0’), provide us information about the diameter of the coin in millimetres. So, this particular battery has a diameter of 20mm.

Finally, the last two digits ‘3’ and ‘2’, indicate the height of the batter in millimetres. But to acquire the height, first take the number and divide it by 10. 

So, 32 divided by 10 will give us a height of 3.2mm. 

CR2032 battery voltage and current capacity ratings  

As we saw earlier, there are two other important characteristics when it comes to selecting the right battery for a particular electronic device;

• Voltage
• Current capacity 

All electrical and electronic devices require a voltage to operate. Without voltage the device might as well be a paper weight. 

The CR2032 has a voltage range of 3 – 3.7 volts.

The next characteristic is current capacity, which is defined by the total amount of charge that a battery is capable of storing (much like how much water a bottle is capable of storing, if water represents the current).

Larger batteries have their current capacities shown in Amp-Hours (Ah), while smaller batteries (like CR2032 coin cell batteries), have their capacities given in Milli-Amp-Hours (mAh).

The CR2032 has a current capacity ranging from 230mAh – 1400mAh.

Are CR2032 primary or secondary batteries?

CR2032 batteries are traditionally primary. 

If you were to go to your local grocery or hardware store, the CR2032 batteries that are available there would be the primary variety. 

This means that you would only be able to use the battery once and then dispose of it. 

However, CR2032 batteries are available as secondary batteries which means you can use them multiple times.

They are readily available online, or at specialised electronic stores. 

Different applications that CR2032 batteries are used for

So, now that we have taken a closer look at the CR2032 battery, we can have a look at all the applications that are perfect for this type of battery.

Electrical and electronic devices come in a variety of sizes from the ones that sit on a desktop, to ones that can fit in your pocket. 

We now know that batteries come in a variety of shapes and sizes to suit the range of sizes of these devices. 

The CR2032 is a smaller sized battery compared to its peers. This makes it perfect for smaller devices. 

But what exact applications are CR2032 batteries used for? 

Let’s take a look. 

Note, CR2032 batteries can literally be found in every small electronic device, so this list will try to divide the applications into different categories. 

This is not an exhaustive list by any means. 

Application #1 where CR2032 batteries are used: Small toys

If you were a kid growing up in the 90’s, you would have been limited by the number of electronic toys available (which is not necessarily a bad thing). 

But, fast forward to the present day, and if you are a kid now, you are spoiled for choice when it comes to toys and their complexity.  

Many toys are now electronic giving them a lot more bells and whistles. 

Smaller toys that aren’t too complicated, will use CR2032 batteries as a source of power. 

Application #2 where CR2032 batteries are used: Computer motherboard

No, CR2032 batteries do not power your computer (if they could that would be amazing)! 

Rather, CR2032 batteries are used on motherboards to help power the internal clock of the microchip when power is removed from the system.

This ensures the system is running smoothly and isn’t always reset when you turn the power off. 

CR2032 batteries are used in many other systems other than a computer motherboard, to power internal clocks. 

Application #3 where CR2032 batteries are used: Key-chain accessories

While keychains were invented to keep your keys secure, whether it be for your car, house, office, lockbox, etc, they now have added accessories that can be added.

Many of these additional accessories are electronic and require a source of power. 

Things such as car key fobs, mini flashlights, bluetooth GPS systems, keyfinder, smart tags, and so much more. 

CR2032 batteries are used for these accessories to ensure they have the power to operate efficiently. 

Application #4 where CR2032 batteries are used: Remote controls

Ah, how would we live in a world without the awesome power of the remote control. This ever useful device ensures we don’t have to get up from our comfy resting place to constantly go change the TV channel.

But, the remote is not just limited to the TV. There is a remote for many other applications such as; stereo systems, air conditioning units, lighting systems, etc.

Depending on the complexity (and size) of the remote, many of them use CR2032 batteries. 

Application #5 where CR2032 batteries are used: Smart doorbells

Gone are the days where you would just knock or ring a simple doorbell to make your presence known to the owner of the house.

Nowadays, doorbells have gotten a whole lot smarter.

They can now sense motion, livestream video,  record audio and video, have fingerprint sensors, and much more. 

Again, depending on the complexity of the doorbell, you will most likely find CR2032 batteries. 

Application #6 where CR2032 batteries are used: Medical

They say prevention is the best cure and knowing what the problem is ahead of time can be the difference between life and death.

When it comes to our health, Doctors are the all knowing wizards who can shed light on many of the issues that might arise in our lives. 

However, we might not always have access to them, or they themselves have a limit to their capability. 

For example, a doctor cannot precisely tell you the level of your blood sugar. 

Thankfully medical devices have been invented to do things that us humans are limited and aid us to solve problems.

And now, we can take these devices with us home to ensure we stay ahead of problems before they become, well, a problem. 

CR2032 batteries are used for many  portable devices that include Oximeters, portable blood pressure monitors, cardio checks, blood glucose metres, and much more. 

There are also devices known as Medic Alert Bracelets that can be worn (on the wrist) by vulnerable patients. 

This allows them to notify emergency services such as an Ambulance in the event they might be home alone and a life threatening situation arises.

Application #7 where CR2032 batteries are used: Wearable electronics

Whether you are into cosplay (costume play), or want to stay connected with the world, you are in luck thanks to the advancement of technology.

Electronics have gotten smaller which means that you can now wear them!

Smartwatches are becoming ever popular allowing you to stay in contact with loved ones, monitor your heartbeat, calculate how fast you are running, how far you have travelled and so much more.

Also, the fashion and cosplay world have benefited tremendously with these smaller electronics allowing them to design costumes otherwise unimaginable. 

Application #8 where CR2032 batteries are used: Miscellaneous

This section isn’t really a category, rather a list of the many other devices that CR2032 batteries are used for which include;

• Calculators
• Vernier callipers
• Electronic dog collars
• Mini Flashlights
• Bicycle lights
• Guitar tuners
• Remote weather stations
• Digital kitchen scales 
• Wireless mouse 
• MP3 player 
• Mini clocks
• Watches

As you can see, the list has a wide variety of applications showing us that the CR2032 battery has many areas where it can be used.

Again, just to reiterate, this isn’t an exhaustive list by any means. 

Why are CR2032 batteries used for the above applications  

The most obvious reason that a CR2032 is used in the applications named above is because of its physical dimension.

It is a small battery that fits the needs of the devices it is used for. 

Other than that, all the devices mentioned do not really require much current to operate. They tend to draw current in the uA (micro ampere) range.

As you can imagine, the CR2032 isn’t really a battery that would be able to hold that much current. Therefore it is a perfect candidate for these smaller devices that require less current. 

Are primary and secondary CR2032 batteries used for the same applications?

This depends entirely on the needs of the device, and the application it is used for. 

If the device is used consistently, it is going to lose charge much faster than if it wasn’t. In this scenario, a secondary (rechargeable) CR2032 battery is ideal.

This will save you time, money, and impacts on the environment having to constantly dispose and replace the batteries. 

A device like a smartwatch would benefit from having a rechargeable CR2032 battery.

However, if the device doesn’t draw too much power, and isn’t put under much stress (load wise), it will last a long time with a single CR2032 battery. 

In this instance, a primary (non-rechargeable) CR2032 battery is the perfect option. A device such as a mini clock, which draws minuscule current would benefit from primary CR2032 batteries.

The post What are CR2032 batteries used for? appeared first on Electronic Guidebook.

They are a series of small Light Emitting Diodes (LED’s) that run along a string similar to Christmas Lights.

However, christmas lights use bigger, much larger LEDs compared to fairy lights. 

Due to the size of the LEDs used in fairy lights, they aren’t used to illuminate spaces but rather used as decoration. 

Fairy lights are designed to be powered with batteries as they are used in applications away from power sources as well as to make them a bit more aesthetically pleasing. 

But, how long do batteries last in fairy lights? The standard batteries that come with fairy lights last around 5- 25 hours depending on the length of the fairy lights. Below is a table summarizing the different lengths and how long the batteries will last. Note, this is an estimate based on calculations in an ideal situation.

However, how long  batteries last in fairy lights comes down to many factors which include;

• Battery capacity
• Current consumption of  the LEDs used in the fairy light
• Length of fairy lights (more lights = greater current consumption) 
• Quality of batteries 
• How long the fairy lights are used for 

In the following article I will list in more detail these factors and give you guidelines on how to roughly calculate how long the batteries and fairy lights you are using will last. 

As, not all the factors will be the same for everyone, values will vary.

Factors that affect how long batteries last in fairy lights

The value of 5 – 25 hours that I mentioned earlier is just an estimate of how long standard Coin cell batteries, plus a standard set of fairy lights will last for. 

But, there are many other factors that play a part in determining whether the batteries will last for a longer or shorter amount of time. 

Let’s take a look at them.

Factor #1 of how long batteries last in fairy lights: Battery capacity

The first major factor which has a large influence on how long batteries in fairy lights last for is the Battery’s Capacity. 

Battery capacity is defined as the amount of charge a battery can hold.

A great analogy for this is a car’s fuel tank.

Some cars have bigger fuel tanks than others, giving them the ability to hold more fuel and thus allow them to travel farther. 

This is the same for a battery. 

However, while physical dimension does play a role in determining it’s capacity, Chemical composition plays a big role too. 

An important value that indicates a battery’s capacity is it’s Amp-Hour (Ah) or milliamp-Hour (mAh) rating.

These ratings tell us how many amperes( or milliamperes) a battery can supply for one hour. Bigger batteries will tend to have their ratings in Ah, while smaller batteries will have it in mAh. 

For example, let’s say we have a AA sized battery which has a battery capacity of 500mAh.

This tells us that the battery can deliver up to 500mA for an hour or, 100mA for 5 hours, or 50mA for 10 hours.

To calculate how long a battery will last (in hours), we divide its capacity by the current draw of the circuit.

This rating will ultimately determine how long those batteries in your fairy lights will last for which can be found on most batteries. 

If the battery does not display these values, you can search the brand of battery online and check its datasheet which should indicate its battery capacity.

The higher the Ah/mAh rating the battery has, the more charge it can hold. 

Factor #2  of how long batteries last in fairy lights: Current consumption of Lights

The battery’s capacity is only one part of the equation when it comes to how long it will last when powering electronic devices such as fairy lights.

The second factor is Current Consumption of the lights used in fairy lights. 

An example would be the best way to illustrate this. 

Let’s use the same battery capacity in the previous example of 500mAh.

This time the battery will be powering two different light sources, both of which have different current consumptions.

As you can see the battery capacity is the same in both scenarios, however, how long the battery lasts for changes. 

This is due to the different currents required by each LED in each scenario. 

The LED in scenario A consumes 50mA and therefore the battery will last for 10 hours.

Whereas, the LED in scenario B consumes 100mA which means it will last for 5 hours.

A 50% decrease in time. 

So, the amount of current the type of light used in fairy lights consumes, plays a large part in how long the battery will last for. 

Different types of fairy lights

Fairy lights use Light Emitting Diodes (LED’s).

But, LEDs vary in size, colour, brightness, angle of illumination etc.

Depending on the LED’s characteristic, it will draw different amounts of current. 

A smaller LED will require much less current to operate compared to a bigger one. 

Also, the brighter the LED, the more current it will draw which is going to drain a battery much faster. 

Factor #3  of how long batteries last in fairy lights: Length of fairy lights

Next on the list of factors that affect how long batteries will last in your fairy lights, is its length.

Fairy lights come in a variety of lengths from 1m, 2m, 3m, 5m and more. 

How does the length affect the battery?

Increasing the length means the number of LED’s are going to increase across the length of the fairy light.

The more LEDs are going to add to the overall power consumption (which comes down to some electronics theory). 

In a Series circuit the current supplied by the battery remains the same throughout the circuit, but the voltage is divided among the components. 

Adding more components such as LED’s is going to increase the power consumption of the overall circuit. 

We saw earlier the current capacity of a battery given in Amp-Hours, or milliamp-hours. 

But, to calculate more effectively how long a battery will last with multiple LEDs it is better to look at the battery’s Power capacity (Wh). 

To obtain the power capacity we simply multiply the current capacity of the battery by its nominal voltage. 

Say, we have a 3V battery whose current capacity is 250mAh, its power capacity will be 750mWh or 0.75Wh.

Let’s take a look at a quick example.

Below is a circuit with a voltage supply and one single LED.

To calculate how much power the LED consumes we use the power formula; P = V x I.

Giving a power value of 34mW for the LED.

The power capacity of the battery is 750mWh (3V x 250mAh).

Dividing the power capacity of the battery (750mWh) by the power consumed by the LED (34mW) gives us the value of how long the battery will last for which equals 22 hours. 

Now let’s add another LED as seen below.

The voltage and current capacity of the battery remain the same. 

But, by adding a second LED (of the same value), the overall power consumption of the battery is doubled (34mW x 2 = 68mW).
Now, when we divide the power capacity of the battery by the overall power consumption of the two LEDs, we get 11 hours.

Note, as you add more LEDs, the voltage drop across is going to increase. To combat this, you will need to increase the value of the supply voltage. 

This is why fairy lights greater than 2m (6.5ft) in length, will require more batteries. 

Factor #4 of how long batteries last in fairy lights: Quality of batteries

The quality of battery used in the fairy lights is another factor that will determine whether your fairy lights last through the night or just half of it.

Cheaper batteries are manufactured to cut down on overall cost with the end game of making more profit. 

This comes at another cost however of cheaper materials being used. This greatly reduces the overall performance of the battery which will be evident when your fairy lights turn prematurely. 

So, check the stock battery that comes with your fairy light and make sure it is a good quality, reputable brand. 

Factor #5 of how long batteries last in fairy lights: How long it is left on for

Finally, on the list of factors of how long batteries will last in fairy light, is how long you leave them on for.

This might seem like a no brainer, but it’s worth noting. 

If the fairy light is turned off after a short period of time, this going to mean that the battery will last for longer than just keeping it on when not needed.

Turning them off when not needed can extend the battery’s life for weeks.

How long do the standard batteries last in fairy lights?

As there are different fairy lights as well as batteries, knowing exactly how long a battery will last in your particular case will be hard. 

But, we can make a rough estimate of the standard batteries as well as LEDs used. 

As the length of a fairy light increases, the voltage needs to increase as well to supply the LEDs with enough current to turn them on. 

So, the longer the fairy light, the more batteries are required. 

Coin Cells (CR2032) are the common type of battery used to power fairy lights due to their sleek design. This means the battery case can be smaller making the overall setup easier to manage. 

CR2032’s are the standard brand supplied when you buy most fairy lights (if any batteries are supplied). So, I will use them for my calculations.

They have a nominal voltage of 3V and battery capacity of 250mAh.

The table below summarizes the rough estimates of how batteries will last for different lengths of fairy lights.

Again, these are all just estimates for an ideal situation. There are many variables that will affect these values.

Note, when you double the voltage of a battery (by connecting it in series), it’s battery capacity remains the same. This is why for lengths 3-5m, the number of hours decreases. 

To increase the battery capacity using two batteries, you will have to connect them in parallel. 

How to make fairy light last longer using batteries

Fairy lights are designed to be operated by batteries since they are used in applications like temporary decoration setups in weddings, parties, etc.

So, plugging them into a power outlet isn’t an option to make them last longer. 

But, fear not! There are a couple of things you can do to extend the life of your fairy lights. 

Tip #1 making batteries last longer in fairy lights: Turn them off

The first tip is the simplest so I thought I’d get it out the way and is to turn the fairy lights off.

If you do not require to run them for long periods of time, turn them off. This could extend the batteries for weeks on end! 

Tip #2 making batteries last longer in fairy lights: Use higher capacity batteries

As you now know, the higher the battery capacity, the longer that your batteries will last in fairy lights. 

The stock batteries supplied with the fairy lights might not have sufficient battery capacity, so you might have to replace them with ones with higher battery capacity. 

Remember to invest in good quality batteries as well. 

Tip #3 making batteries last longer in fairy lights: Opt for smaller LED fairy lights

There are many different styles of fairy lights available for many different occasions. 

The type of light, as well as size is going to vary. 

If you need your fairy lights to last for long amounts of time, opt for ones that use smaller sized LEDs as they will consume less current. 

Also, if you only require 3m of fairy light, do not buy one that is 5m in length. 

Benefits of using rechargeable batteries for fairy lights

You can only extend the life of batteries so much before you will have to throw them in the bin. 

Using disposable batteries is not only harmful to the environment, but is a waste of money.

Rechargeable batteries, as the name suggests, are batteries that can be recharged and used again and again.

This means that you can reuse them with your fairy lights without having to throw them out which is going to be beneficial for the environment and your bank account.

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