LR44 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 fundamental principle in an electrochemical cell is spontaneous redox reactions in two electrodes separated by an electrolyte, which is a substance that is ionic conductive and electrically insulated.

An LR44 battery is a 1.5V alkaline button cell used in various applications such as remote controls, car keys, garage openers, micro LED flashlights, calculators, toys, etc. It is one of the most used button cells. The LR44 battery has an operating temperature ranging from 0°C- 60°C, while the optimal temperature is 20°C.

Dimensions and Weight of LR44 Battery

LR44 batteries (11.6 mm x 5.4 mm) have a nominal diameter of 11.6 millimeters. The overall height is 5.4 millimeters. Its weight is only 1.96 grams (0.0691 oz).

It has a typical capacity of about 140 mAh. As with all similar batteries, the LR44 battery’s capacity depends on the current drain and actual cutoff voltage of the powered device.

Composition of LR44 Battery

The LR44 battery is a 1.5V alkaline button cell. The 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 alkaline battery gets its name because it has an alkaline electrolyte of potassium hydroxide (KOH) instead of the acidic ammonium chloride (NH₄Cl) or zinc chloride (ZnCl₂) electrolyte of the zinc–carbon batteries. The alkaline cell was introduced to the market in 1959 but did not become more common than the Zinc-carbon cell until around 1980.

Characteristics of LR44 Batteries

To compare and understand the capability of each battery, some important parameters are characteristic of each battery, also within a type of battery. These parameters are a reference when a battery is needed, and specific qualities are required since batteries are used in all types of devices and for infinite purposes.

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.

When the circuit is closed, the stronger attraction for the electrons by the cathode (e.g. manganese dioxide in alkaline batteries) will pull the electrons from the anode (e.g. zinc) through the wire in the circuit to the cathode electrode. This battery chemical reaction, this flow of electrons through the wire, is electricity.

If we go into detail, batteries convert chemical energy directly to electrical energy. Chemical energy can be stored, for example, in Zn or Li, which are high-energy metals because they are not stabilized by d-electron bonding, unlike transition metals.

Even though a wide range of types of batteries exists with different combinations of materials, all of them use the same principle of the oxidation-reduction reaction. In an electrochemical cell, spontaneous redox reactions take place in two electrodes separated by an electrolyte, which is an ionic conductive and electrically insulated substance. The redox reaction is a chemical reaction that produces a change in the oxidation states of the atoms involved. Electrons are transferred from one element to another. As a result, the donor element, which is the anode, is oxidized (loses electrons), and the receiver element, the cathode, is reduced (gains electrons).

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.