The Design and Construction of Auto Cut-off Car Battery Charger

The Design and Construction of Auto Cut-off Car Battery Charger

ABSTRACT

This project comprises many chapters that deal extensively with designs and construction of battery charger with auto-cut off which is capable of charging a 12 volts battery. In this construction research, designs were carried out which historic research was used to break down and evaluate to a low level understating of what an auto-cut of charger system is all and how it can be constructed and the main purpose of the project. The charging current, as well as the power to the circuit, is obtained from 1 0 – 18 volts 2 Ampere step down transformer. The law voltage AC can be rectified by the bridge rectifier comprising D1 through D4 and made ripple-free by the smoothing capacitor C1 for charging purposes, 18V DC is used while to power the circuit, 9 volts regulated DC form IC1 is used. IC2 (CA 3140) is used as a simple voltage comparator to drive the relay. After the series steps of inversion pure DC is achieved that can charge a specified DC battery. The relay saves as the Tripping command to the pin i.e to operate automatically when the battery is fully charged and when is weak.

CHAPTER ONE

1.0 INTRODUCTION

1.1 Background of the Study

In the context of a renewable energy source, a device that consists of electrodes and electrolytes for the storage of chemical energy, but brings about a reaction between its electrodes and the electrolyte in a way to cause the flow of electrons through an external circuit is known as a battery the circuitry to recharge the batteries in a portable product is an important part of any power supply design. The complexity and cost of the charging system
primarily depends on the type of battery and the recharge time.

1.2 Charging Formation

In the realm of battery charging, charging methods are usually separated into two general categories.

Fast charging is typically a system that can recharge a battery in about one or two hours.

Slow charging: This is usually referred to as an overnight recharge, i.e it is usually defined as a charging current that can be applied to the battery indefinitely without damaging the cell. (This method is sometimes referred to as trickle charging).

The maximum rate of trickle charging which is safe for a given cell type if dependent on both the battery chemistry and the cell construction when the cell is fully charged, continued charging causes gas to form within the cell. All of the gas formed must be able to recombine internally, or pressure will build up within the cell eventually leading to gas release through the opening of the internal vent (which reduces the life span of the cell).

This means that the maximum safe trickle charge rate is highly dependent on battery chemistry, but also the construction of the internal electrodes.

1.3 Types of Batteries

Primary (Dry Cell): those whose electrolyte dries up when used to its ampere-hour rating and cannot be recharged. Dry cell batteries are different from wet cells because their electrolytes are contained in a low-moisture paste. Regardless of their sizes, they have the same basic components. At the centre of each is a Rod called the cathode which is often made up of carbon and surrounded by an electrolyte paste. Different chemicals can be used to create this paste such as ammonium chloride and manganese dioxide, depending on the type of battery. The cathode and electrolyte paste is wrapped in paper or cardboard and sealed into a metal cylinder called an anode which is typically made of zinc.

Secondary (Wet Cell): It is the type whose chemical energy can restore through a charging process. Although there are different types of secondary battery which comprises lead-acid, nickel-cadmium, and silver-zinc battery.

A wet cell is a type that operates by liquid electrolytic solution, it often runs down move quickly in a hot climate because the heat causes the plates to either from the electrolyte solution.

Furthermore, a battery is a combination of cells connected and cells is of importance partially where maximum performance and life are obtained. As long as a battery is in use, it stores chemical energy which is being converted to electrical energy falls. This falls in chemical energy leads to a corresponding fall in terminal voltage.

A constant potential method of charging is adopted in this project work it is a phenomenon whereby the alternating voltage from the main is converted to direct voltage through rectification.

The direct current from the rectifier is then passed through the battery that is being charged in the reversed direction in which the battery supplies current to the external circuit. The charger is intended to charge batteries with a terminal voltage of up to 12 volts. It incorporates a sensing technique to monitor when the battery has been charged to its rated terminal voltage to automatically cut off supply to the battery.

Centuries ago the use of tricycles was established with the help of coal engines or horses to ride on the same paved horizon. Before the charger circuits with nickel-cadmium, Nickel-metal hydride, and lithium-ion batteries. Which can be charged and can retain charged particles inside until it is used up with its connected circuit for operation.

1.6 Aims and Objective

The main purpose of this project work is the major of construct a system that has the ability measures of recharging a battery when it runs down. The design conforms to an auto charging cut off the circuit that operates when the battery is fully charged.

1.7 Scope of the Study

The battery charger is a device that is well designed to perform the function of converting 50Hz or 60Hz Ac into an equivalent variable DC output. The DC produced after the rectification process is then applied directly in the charging of our batteries. The battery charger can perform the function of charging a 12V battery, 24-volt battery depending on the desired specification of construction.

This project design function basically to recharge batteries not exceeding 36 volts and a lineup of batteries not exceeding ten in numbers. The current supply of the charging system does not exceed the 3amp per charging ratio of the line.

1.8 Report Organization

Six chapters were converted in the course of the design and development of this project. The chapters and their contents are as follows:

Chapter one is the introductory chapter that gives the aims, scope and limitations of the project.

Chapter two is the literature review, it deliberates on different related works done by several authors with dates. It also discusses the limitations of some of these works.

Chapter three discusses the design methodology of the project. Also discussed, is the requirement analysis which is all the information, gathered from wide research on battery charger systems.

Chapter four deals with the system testing and evaluation also how the components were tested.

Chapter five is the Bill of Engineering Measurement and Evaluation (BEME) i.e the component last unit and Evaluation.

Chapter six is the summary, conclusion and recommendation. The contribution of the project, achievements and problems for further enhancement, and references are discussed in this chapter.