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ToggleWhat Is A Button Battery?
Button batteries are extremely small batteries used in different household items and devices. Due to their size, they are also called flat or coin cells and are found in applications like calculators, watches, and medical instruments.
Although small, button batteries have become prominent in our daily activities, and it is important to understand what they are and how they are named.
Button batteries are available in different technologies and sizes. Plus, each technology has its suitable area of use.
This guide takes a look at the naming procedures for button batteries, types, and uses:
Naming Convention for Button Batteries
Coin batteries are named based on a couple of factors, including the size and voltage. Here is an overview of how a button-size battery is named:
Prefix Letter: the first letter, conned as the prefix letter, is the letter that starts the name of a button battery, which usually connotes the battery’s chemistry or metal type featured in the anode. For example, a flat battery that starts with “LR” is an alkaline battery, while “CR” means lithium batteries, and SR stands for silver-oxide batteries with heavy metal and longevity.
Diameter: the diameter of a button battery is given in millimeters in the name and comes after the prefix letter. For example, “44” in “SR44” gives an idea of its diameter, which is 11.6m.
Thickness: the thickness and height of a battery can be derived from the second number in the name, and it is also given in diameter. For example, “44” in SR44 means the battery is 5.4 tall.
Voltage: every chemistry of a button-sized battery comes with its voltage rating. For example, silver-oxide batteries have a voltage of 1.55V.
Additional Information: some battery names come with additional letters or numbers to provide more information about other features, especially when multiple batteries have similar sizes.
For a deeper understanding of naming a button battery, let’s consider the CR2032.
In CR2032, “CR” is the prefix that means the battery is a lithium battery, 20 means the battery has a diameter of 20mm, while “32” indicates a thickness of 3.2mm. However, the voltage for every lithium battery varies between 3 and 3.6 volts since it is a lithium battery.
Although this is the typical naming convention of button batteries, it is important to note that manufacturers may use slightly different naming procedures. Hence, it makes sense to consult a battery packaging for accurate information about the battery.
Button Battery Sizes and Properties
Before choosing a button battery for any device, it is important to identify the right size of the battery. Button batteries are available in different sizes, courtesy of their diameter and thickness. Here are common sizes of button batteries and their uses:
LR (Alkaline) Button Battery
LR43 (AG12): Diameter of 11.6mm, thickness of 4.2mm, 1.5V, commonly used in medical devices and toys.
LR41 (AG3): Diameter of 7.9mm, height of 3.6mm, typically 1.5V, suitable for calculators, toys and laser pointers.
LR44(AG13): Diameter of 11.6mm, thickness of 5.4mm, typically 1.5V, commonly used in toys, electronic games and small electronic devices.
LR54 (AG10): Diameter of 11.6mm, thickness of 3.1mm, typically 1.5V, ideal for toys, calculators, and laser pointers.
LR59 (AG2): Diameter of 7.9mm, thickness of 2.15mm, typically 1.5V, used in small electronic toys and gadgets.
LR66 (AG4): Diameter of 6.8mm, thickness of 2.6mm, 1.5V, commonly found in watches, calculators, and small medical devices.
LR626 (AG4): Diameter of 6.8mm, thickness of 2.6mm, 1.5V. They are ideal for watches, toys, and digital thermometers.
LR1120 (AG8): Diameter of 11.6mm, thickness of 2.1mm, 1.5V. Applications include calculators, toys, and electronic clocks.
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Benefits of LR batteries
LR batteries are a suitable choice of coin cells for a wide range of applications, ranging from toys to watches, due to their availability and cost-effectiveness. They are relatively cheap and readily available for customers looking for something cheap to power their small gadgets.
Another important advantage of flat batteries is their excellent performance at room temperature. Plus, they come with no risk of leakage, a common cause of damage in electronic devices.
Limitation of LR batteries
Although they offer several benefits over their counterpart button batteries, LR batteries come with a few downsides. The major limitation of LR batteries is low energy density. LR batteries hold lower energy than many other button batteries like lithium batteries and hence easily get drained, especially when used in applications with constant power supply.
LR batteries’ short shelf life is also another drawback of the battery chemistry. Although they can be stored for a considerable amount of time, their storage is limited to only a few years. LR batteries tend to drop in performance after a few years of storage, even when not used.
It is also worth noting that LR batteries have diminished performance in cold temperatures. This makes them a less suitable option for applications in cold environments, and they are not recommended for outdoor use.
What’s more, LR batteries have special recycling requirements, as the batteries contain chemicals that can be harmful to the environment if not well handled. Hence, they should be disposed of carefully. Unfortunately, not all areas have the proper recycling facilities for this button battery technology.
CR (Lithium) Button Batteries
CR927: 9.5mm in diameter, thickness of 2.7mm, with applications in small LED lights or electronic jewelry.
CR1025: 10mm, thickness of 2.5mm in diameter, commonly used in compact electronic devices.
CR1225: 12.5mm, thickness of 2.5mm in diameter, used in memory backup applications and small electronic devices.
CR1620: 16mm, thickness of 2.0mm in diameter, used in car remote keys and small electronic gadgets.
CR1632: 16mm, thickness of 3.2mm in diameter, commonly found in automotive key fobs and small electronics.
CR2016: 20mm, thickness of 1.6mm, with applications in small remote controllers and medical devices.
CR2025: Diameter of 20mm in diameter, thickness of 2.5mm, often used in electronic games and other small electronic devices.
CR2330: 23mm in diameter, thickness of 3.0mm, used in some car remotes and medical devices.
CR2032: 20mm in diameter, thickness of 3.2mm, widely used in motherboards, calculators, and remote controls.
CR2450: 24mm in diameter, thickness of 5.0mm, commonly used in larger devices requiring a longer life.
CR3032: 30mm in diameter, thickness of 3.2mm, often found in larger electronic devices with higher power capacity
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Benefits of CR Batteries
CR batteries feature lithium battery chemistry and are popular in a variety of applications thanks to their compact size and reliable power supply.
One obvious advantage of CR batteries over LR batteries is the higher energy capacity. CR batteries can hold more energy than their counterpart LR and last longer in devices they power. Hence, they are a better option for applications where a constant power supply is needed.
Also, CR batteries beat LR batteries on the shelf life front and, when stored properly, can last for several years without losing performance. This feature makes them a great choice for infrequently used and emergency devices.
Another credit to CR batteries is rooted in their high-reliability rating and impressive performance in a wide range of temperatures, as they don’t drop in performance when used in extremely cold or hot temperatures. Hence, they are a better choice for outdoor uses.
Limitations of CR batteries
Although they have a load of benefits over other batteries, CR battery technology has its limitations, too. Here are a few areas where CR batteries lag:
One common concern about CR batteries is their high cost. Lithium batteries are generally more expensive than alkaline batteries, although this is compensated for by high energy density. Hence, customers on low budgets might want to drop CR batteries for LR or other options.
Also, the high energy density in lithium batteries can be a setback for the batteries in terms of chemical leakage. The chemicals are strong and can damage the device they power when the batteries rupture. This also means that the batteries can pose a threat to human health and are therefore not safe for use in kid toys and other devices.
It is also worth noting that disposing of lithium batteries can be harmful to the environment. While the chemicals are not as harmful as chemicals in other batteries, they can contribute to pollution if proper recycling procedures are not followed.
SR (Silver Oxide) Button Battery
SR416SW(337): 4.8mm in diameter, thickness of 1.6mm, 1.55V, used in very compact devices, such as hearing aids and small electronic gadgets.
SR516SW (317): 5.8mm in diameter, thickness of 1.6mm, 1.55V, used in small electronic devices, including some wearable technology.
SR626SW (377): 6.8mm in diameter, thickness of 2.6mm, 1.55V, used in watches.
SR621SW (364): 6.8mm in diameter, thickness of 2.1mm, 1.55V, used in watches.
SR721 (362): 7.9mm in diameter, thickness of 2.1mm, 1.55V, used in watches and small electronic instruments.
SR927SW (395/399): 9.5mm in diameter, thickness of 2.7mm, 1.55V, commonly used in precision instruments and high-end watches.
Benefits of SR batteries
As highlighted above, silver oxide batteries are commonly used in precision electronic devices like medical devices, watches, and hearing aids, thanks to consistent, precise power supply. With stable voltage output from SR batteries, these devices can function effectively with accurate results.
Also, thanks to higher energy density, SR batteries can hold enough energy juice needed for a longer lifespan. Silver oxide batteries can power devices for a longer time than their LR competitors, reducing the need for frequent battery changes.
Although they are expensive upfront, a longer lifespan also means low costs in the long run since the batteries can serve users for longer periods.
Limits of SR batteries
One major concern about SR button batteries is the high upfront costs. Silver oxide batteries are more expensive than LR and CR batteries, which is linked to the high cost of silver. Hence, they are not an ideal option for low-budget users or disposable devices.
Additionally, although SR batteries boast high energy capacity and overall longevity, they are not as long-serving as lithium batteries, especially in high-drain applications.
What is more, it is also worth noting that the use of SR batteries poses environmental threats. The extraction and use of silver can contribute to environmental pollution, and since SR batteries feature silver, they are guilty of this setback.
Zinc Air Button Battery
ZA675 (Blue Tab): 11.6mm in diameter, thickness of 5.4mm, 1.4V, used in hearing aids, characterized by their high energy density and long life.
ZA312 (Brown Tab): 7.9mm in diameter, thickness of 3.6mm, 1.4V, used in various hearing devices.
PR70 (312 Hearing Aid Battery): 7.9mm in diameter, thickness of 3.6mm, 1.4V, majorly found in hearing aids, thanks to a balance of size and power for small devices.
PR48 (13 Hearing Aid Battery): 7.9mm in diameter, thickness of 5.4mm, 1.4V, used in hearing aids due to longer life, courtesy of its larger size compared to other batteries in this use.
Benefits of Zinc-air button batteries
High One outstanding feature of zinc air is an exceptionally high energy density compared to other battery technologies like silver and alkaline. This impressive energy density is linked to the unique mechanism used in the battery technology, which leverages oxygen from the air for its chemical reaction.
This higher energy density means ZA batteries can last longer when subjected to the same usage as other batteries. This reduces the need for replacement, ultimately cutting costs and maintenance frequency. This feature makes them a more suitable option for hearing devices due to the difficulty of replacing batteries.
Also, since zinc air batteries rely mostly on air for their performance, they have a lower chemical threat to humans and the environment, meaning they are safer to use and dispose of.
Limitations of zinc air batteries
The major setback of zinc-air batteries is rooted in their reliance on air for chemical reactions. This means environmental factors like temperature, humidity, and air quality influence the performance of zinc air batteries. For example, high humidity can result in excess moisture that reduces the battery’s performance. Similarly, low air quality can result in clogged air pores of the battery, ultimately reducing the battery’s output.
Additionally, once a ZA battery is activated, it cannot be “switched off”. The batteries are designed for continuous use, and when the seal is removed, and the battery is activated for air, there is no going back. This makes the ZA battery technology a less practical option for intermittent use.
Another limitation of zinc air batteries is that while they leverage oxygen from the air to function, they still feature zinc in their formation. Zinc is a toxic substance that contributes to environmental degradation during mining and processing.
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