This type of batteries are very common in devices such as watches, computers, calculators, remote controls etc .. thanks to its small size is ideal for small devices.

Its very peculiar shape is of cylindrical and flat type, with two discs, one upper connected to the positive pole (4) and one in the lower part connected to the negative pole (5).

According to the model we will find them with voltages of vary between 1.2and 3 V (3).

This type of stack can be divided into two large groups:

• Primary batteries: They are depleted as they are used.
• Secondary batteries: They can be recharged by passing an electric current through them in the opposite direction.

Since there are numerous types of button-type batteries in the market, it is advisable that before buying it, the model of the battery is verified, all battery models inu upper part indicate the model, normally this reference begins with two or three letters (1) followed by a numbering (2).

It is mandatory to dispose of exhausted batteries at a recycling point, as these types of batteries are highly polluting due to their composition.

1. Metal cathode (+).
2. Zinc anode (-).
3. Zinc (Electrolytic).
4. Isolation.
5. Separator (porous).
6. PaAg2o sta.

Inside the button cells you will find 4 types according to their chemical composition.

• Alkaline: They are the most common, are composed of zinc as anode and manganese dioxide (MnO2) as cathode, its voltage is 1.5 volts, the most common: LR54, LR44, LR43, LR9.
• Lithium: Its chemical composition can be Manganese-Lithium Dioxide, LiMnO2, Polycarbonate-Lithium Monofluoride or Thionyl Chloride-LiUncle Tadiran. The most common, CR1025, CR1216, CR1220, BR1225, CR1612, CR1616, CR1620, CR1632, CR2016, CR2025, BR/CR2032, BR2325, BR/CR2330, CR2354, CR2450, CR2477, CR3032. Their voltages vary between 3 and 3.6 volts.
• Silver oxide: Very good at low temperatures, its voltage is 1.55 volts. The most common, SR41, SR42, SR43, SR44, SR45, SR48, SR54, SR55, SR57, SR58, SR59, SR60, SR62, SR63, SR64, SR65, SR66, SR67, SR68, SR69.
• Zinc air cells: Normally used in hearing aids, their voltage is 1.4 volts., The most common: PR70, PR48, PR41 or PR44.

Within the wide range of batteries on the market we can differentiate two large groups, disposable batteries and rechargeable batteries.
Disposable batteries are those that only allow a single use and when they are exhausted they can not be recharged. These batteries can store their energy for years.

Rechargeable batteries are those that can be recharged once exhausted. This type is losing charge when they are storedaccording to voltage. The most common we can find them of 1.2V and 3.7V

As a last point you have to take into account that lithium batteries, Lipo, Life etc. Due to its composition, specific loaders should be used.