Design And Construction Of An Automatic Battery Charger With Priotective Circuit

ABSTRACT

Battery charger is an electrical device employed for charging batteries. A battery charger is used to put energy into a secondary cell or rechargeable battery by forcing an electric current through it. The aim of this work is to build an automatic battery charger for a 12v lead acid battery charger. The charger shuts down automatically once the battery attains full charge, say 13.6v. This prevents overcharging of the battery so that, the charger can be left unattended. This automatic tripping off is carried out with the help of the transistor and relay.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• PROBLEM STATEMENT
• AIM/OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• APPLICATION OF THE PROJECT
• LIMITATION OF THE PROJECT
• ADVANTAGES OF THE PROJECT
• METHODOLOGY
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

2.1      REVIEW OF BATTERY CHARGER

2.2      HISTORICAL BACKGROUND OF BATTERY CHARGER

2.3      REVIEW OF RECHARGEABLE BATTERY

2.4      REVIEW OF CHARGER UNITS

2.4.1 SUPPLY UNIT

2.4.2 THE RECTIFYING UNIT

2.4.3 THE SMOOTHING UNIT

2.4.4 THE REGULATOR AND REGULATED

2.4.5 D.C CHARGING UNIT

CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1     BLOCK DIAGRAM OF THE SYSTEM

3.2      CIRCUIT DIAGRAM

3.3      CIRCUIT DESCRIPTION

3.4      SYSTEM OPERATION

3.5      DESCRIPTION OF MAJOR COMPONENTS USED

CHAPTER FOUR

4.1            RESULT ANALYSIS

4.1      CONSTRUCTION PROCEDURE AND TESTING

4.2      CASING AND PACKAGING

4.3      ASSEMBLING OF SECTIONS

4.4      TESTING OF SYSTEM OPERATIONOBSERVATIONS

4.6     DIFFICULTIES ENCOUNTERED ON THE SYSTEM

4.7     COST OF PRODUCTION

CHAPTER FIVE

• SUMAMRY
• CONCLUSIONS/SUGGESTIONS

5.3     REFERENCES

CHAPTER ONE

1.0                                                     INTRODUCTION

1.1                                     BACKGROUND OF THE PROJECT

A battery charger is an electrical device employed in charging batteries. A Battery charger comes in various designs and voltage. The choice of a particular and type of charger depends largely on the size of battery or batteries.

The battery charge is built in such a way that it delivers a constant value of d.c current into the battery it is charging in the opposite direction from which current flows on the batteries during discharge one cannot successfully design a battery charge without a fundamental understanding of the accumulator because it also makes up the operation according to [Xie, Z.; Liu, Q.; Chang, Z.; Zhang, X. 2013].

The aim of this work is to build a charger that will automatically shut off the charging process when battery attains full charge thereby protecting the device from overcharge. This prevents the deep charge of the battery. If the battery voltage drops below the 12V, then circuit automatically switch on battery charger.

1.2                                             PROBLEM STATEMENT

Sometimes there is nothing worse than losing all the charges on device such as inverter, especially when you are in the middle of something very important. Usually this happens at the most inconvenient time probably when you are using your inverter to surf the web, in the middle of a browsing or when you are desperate to send an important email or text message. Automatic battery charger with protecting device was invented to overcome this problem and thereby protecting devices from overcharging.

1.3                                        OBJECTIVES OF THE PROJECT

The objective of the project is to design a device that will recharge 12v lead acid battery when discharged and has the capacity to protect the battery from overcharge.

1.4                                      SIGNIFICANCE OF THE PROJECT

This device charges 12v acid battery mainly, however, if the output voltages are adjusted can be used to charge battery of lower or higher voltages. Apart from charging batteries, this device can also be used as a battery level monitor due to the battery level feature it contains. This device has protecting device which protects battery from overcharging. [Xie, Z.; Liu, Q.; Chang, Z.; Zhang, X. 2013]

1.5                                       APPLICATION OF THE PROJECT

Battery charger is used in the following devices for the purpose of recharging devices’ batteries according to (Sequeira, C.A.C, 2011), Such batteries are:

1. It is used in inverter
2. It is used in cellphone
3. It is used in Solar energy system
4. It is used in vehicles
5. It is used in an uninterruptible power supply (UPS), etc.

1.6                                        LIMITATION OF THE PROJECT

The only problem with this device is that it takes longer time to recharge car battery because of the low current output, and it is design only for a 12 battery.

1.7                            ADVANTAGES OF AUTOMATIC CHARGER

Features of this automatic battery charger made it more advantageous than other types and they are as below (Sequeira, 2011):

• Automatic battery charger has an indicator to indicate when the battery is fully charged
• Built in Indications for showing Full, Empty Levels of any type of battery
• It has a manually operated switch that is used to ON and OFF the entire system.
• It composes of in-built active components which stop charging process when the battery is fully charged.
• It consumed less current but generate high current to the load.

1.8                       PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to a 12v battery charger. In this chapter, the background, significance, objective limitation and problem of a 12v battery charger were discussed.

Chapter two is on literature review of a 12v battery charger. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.