Today, button batteries are using in many electronic devices such as calculators, hearing aids, watches, medical devices, etc. This type of battery is easy to recognize as it has a round and narrow shape similar to that of clothing buttons.
Being of such a small size, it makes its energy capacity higher, in this way its charge lasts longer. In addition, the devices in which this type of battery is usually used do not consume a large amount of energy, such as calculators.
Let us know more about these button batteries.
What is a button cell battery?
Button batteries and lithium coin batteries are the small round batteries that we usually find in small electronic devices, such as:
– Remote controls
– Toys and games
– Electronic keychains
– Thermometers picture household devices with button batteries
– Hearing aids
– Bathroom scales
– Watches & Electronic Jewelry
– Christmas ornaments
This type of battery comes in a shape of a squat cylinder and normally the size is 5 to 25 mm in diameter and height is 1 to 6 mm.
Today most of these batteries run on the type of energy we call lithium. At first glance, all button batteries are the same but there are several types, these are the most common:
Alkaline: Within alkaline button batteries there are also several different types with various measures but all have a voltage of 1.5 volts.
Lithium: In the case of this type of battery, its voltage can go up to 3 volts. These batteries offer a fairly long lifespan.
Thionyl Chloride-Lithium: These batteries offer a voltage of 3.6 volts and their useful life reaches 10 years. They are typically using for electricity, gas, and water supply meters.
Silver oxide: its voltage is 1.55 volts. These batteries have a good performance against vibration and a very good performance at low temperatures.
Zinc-air cells: the voltage of this type of button cell is the lowest, operating at 1.4 volts. They are mainly using in hearing aids.
The main characteristic of this type of batteries is that they have high stability against temperature changes, being able to operate at 100% of their performance in temperatures between -20º and + 60º. In addition, another of its characteristics is the duration of its load during storage, losing less than 1% of the load per year.
We must always remember that these batteries are highly polluting for the environment, so when their useful life ends we must recycle them correctly. If you don’t know how to do it, you can go through the following post.
How to store button cell batteries?
It is always advisable to store button cell batteries in a dry and cool place at a normal room temperature. However, it is advisable not to store these batteries in a freeze. Never dispose of button cell batteries in a fire as they may rupture or leak.
How to recharge button cell batteries?
Like all other different types of batteries, button cell batteries can recharge. You can charge using a voltage of a maximum of 3.3 Volts.
How to test button cell batteries?
There was a time when there was a theoretically infallible method to know if a button cell battery was charging or not. Today, we give you a few methods to test if button cell batteries charge or not?
When you passed your tongue over the terminal, the battery gave you a small discharge, then it had a charge. In case the only thing you felt was a metallic and somewhat sour aftertaste, then the pile had passed away.
Another method is to simply drop the stack in an upright position and drop it down the smooth side from a height of four to five centimeters onto a flat surface.
If the battery remains stable and vertical, it is because there is still liquid inside it and therefore it charges. If the battery rocks a lot or even falls, the battery is flat.
How to charge button cell batteries?
There are cases where flat cells use as the main power source. Although these are universal applications that only require low power. It should be assuming that the service life of the application should be long enough that the button battery will deplete during the lifetime of the device. In this case, the user has the option of purchasing a rechargeable equivalent, the LIR2032. It is also important to note that the CR2032 battery is not rechargeable.
How long will it last?
The easiest way to see the life of a battery is to check the total charges in milliamp hours. And then divide that figure by the current draw.
Battery life = 225 milliamp hours / current
In an application that draws 1 constant microampere or less, it results in more than 10 years. This may be true in a case where the battery supplies a computer’s BIOS, but in most cases, the battery must supply more current continuously or in pulses.
Here we can see that if a button cell battery is to supply 0.5 mA (500 microamps) continuously, its output voltage will not drop to 1.6 volts until it has supplied 240 mAh. If on the other hand, it must supply 3.0 mA, it will only be able to supply 155 mAH. So, we can see that the battery will not only last 0.5 / 3.0 or 17% of the expecting time but there will also be an unexpecting 155/240 reduction beyond this, due to increasing demand. Of course, if a circuit cannot operate on less than 2.0 or 2.4 volts, the additional drain will create a further reduction in battery utilization capacity.
If the button cell battery must deal with a pulse demand pattern for current. It will also cause a decrease from its optimal value of 225 mAh. This can be a major problem for Bluetooth-enabled devices. This can be a big problem and designers should seriously consider its ramifications.