6V Battery

An electric battery is essentially a source of DC electrical energy. It converts stored chemical energy into electrical energy through an electrochemical process. This then provides a source of electromotive force to enable currents to flow in electric and electronic circuits. A typical battery consists of one or more voltaic cells. 

The voltage of electric batteries is determined by:

• Chemistry. The potential difference of the materials that compose the positive and negative electrodes in the electrochemical reaction.
• Number of cells. Batteries in series produce a voltage equal to the number of batteries multiplied by the voltage of each individual battery.

The voltage of electric batteries is created by the potential difference of the materials that compose the positive and negative electrodes in the electrochemical reaction.

6V Battery

The six-volt battery, or 6-volt battery, is an electric battery that is typically composed of various cells. It is able to supply a nominal voltage of 9 volts.

There are various types of 6V batteries:

• Lead-acid 6V Battery. This battery is composed of 3 x 2V lead-acid cells. The 6V 4.50Ah battery offers good performance in a wide range of applications, including security and fire systems, medical devices, emergency lighting, and UPS systems. Lead-acid batteries are secondary (rechargeable) batteries that consist of a housing, two lead plates or groups of plates, one of them serving as a positive electrode and the other as a negative electrode, and a filling of 37% sulfuric acid (H₂SO₄) as electrolyte.
• Alkaline 6V batteries. This battery is composed of 4 x 1.5V alkaline cells. For example, 4LR44 can be used for a wide range of consumer electronics, including cameras, remote controls, toys, and more. An alkaline battery (IEC code: L) is a type of primary battery that provides direct electric current from the electrochemical reaction between zinc and manganese dioxide (MnO₂) in the presence of an alkaline electrolyte. The primary alkaline battery is a widely used product, which is essential for powering many portable devices, such as power tools, radios, toys, and remote controls. The most common size of alkaline battery is the well-known AA battery.

Cell Voltage

The voltage of electric batteries is created by the potential difference of the materials that compose the positive and negative electrodes in the electrochemical reaction. 

The voltage produced by each lithium-ion cell is about 3.6 volts. This has many advantages. Being higher than that of the standard nickel-cadmium, nickel metal hydride, and even standard alkaline cells at around 1.5 volts and lead acid at around 2 volts per cell, the voltage of each lithium-ion cell is higher, requiring fewer cells in many battery applications.

Because most of the resulting voltages are around 2V, cells are connected in series to obtain more practical electrical potentials (i.e. 2V lead acid cells are connected in series to obtain a typical 12V battery).

Batteries with voltages greater than 1.5 volts are usually made up of cells connected in series inside a single case. In the 9 volt battery, there are six cells connected in series. The calculation is 6 × 1.5 Volt = 9 Volt.

To know the voltage of a battery, batteries are marked with nominal voltages which is the average voltage a cell outputs when is fully charged, but this may differ from the open circuit voltage.

In addition, some factors like low temperature can decrease the expected voltage output and increase with higher temperature, which is favorable for the electrochemical reactions.

To avoid batteries to discharge below a certain level which could cause damaging the battery, there is a voltage limit called cut-off voltage.

• 1.5V (DC) – A common open circuit voltage for non-rechargeable alkaline batteries (e.g. AAA, AA and C cells). 
• 3V (DC) – Lithium-based primary cells are batteries that have metallic lithium as an anode. The voltage of most lithium-metal cells (e.g. button cells) is 3V.
• 3.8V (DC) – Almost all lithium-ion batteries work at 3.8 volts. In order to make current flow from the charger to the battery, there must be a potential difference. Therefore battery chargers or USBs for almost all smartphones provide a voltage of 5V.
• 12V (DC) – A common voltage for automobile batteries is 12 volts (DC). But this battery consists of six 2V lead cells.

Chemistry of Alkaline Batteries

In simple terms, each battery is designed to keep the cathode and anode separated to prevent a reaction. The stored electrons will only flow when the circuit is closed. This happens when the battery is placed in a device, and the device is turned on.

In an alkaline battery, the negative electrode is zinc, and the positive electrode is high-density manganese dioxide (MnO₂). The alkaline electrolyte of potassium hydroxide, KOH,  is not consumed during the reaction. Only the zinc and MnO₂ are consumed during discharge. The alkaline electrolyte of potassium hydroxide remains, as there are equal amounts of OH⁻ consumed and produced.

The half-reactions are:

Zn_(s) + 2OH⁻_(aq) → ZnO_(s) + H₂O_(l) + 2e⁻ [E_oxidation° = +1.28 V]

2MnO_2(s) + H₂O_(l) + 2e⁻ → Mn₂O_3(s) + 2OH⁻_(aq) [E_reduction° = +0.15 V]

Overall reaction:

Zn_(s) + 2MnO_2(s) ⇌ ZnO_(s) + Mn₂O_3(s) [e° = +1.43 V]

Applying this battery chemistry to the real world, the electrons generated during the reaction are used to power devices when the circuit is closed.

Other Types of Batteries

The following list summarizes notable electric battery types composed of one or more electrochemical cells. Four lists are provided in the table. The first list is a battery classification by size and format. Then, the primary (non-rechargeable) and secondary (rechargeable) cell lists are lists of battery chemistry. The third list is a list of battery applications. The final list is a list of different battery voltages.