Design And Implementation Of 5V DC Li-Ion Battery (Android Phone) Charger With Automatic Control Feed Back

ABSTRACT

This work is on design and construction of an android or cell phone charger with auto cut off feature. This device is designed to charge cell phone, that charges battery automatically, when the battery is charged it will shut off the charger.

The objective of this project is to design and construct an electronic device that will supply electrical energy (charges) to a cell phone battery, in a process to restore the battery’s used up energy which will automatically shut-off immediately the battery is fully charged.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

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

2.5      REVIEW OF DIFFERENT TYPES OF BATTERY CHARGERS

2.6      REVIEW OF CELL PHONE BATTERY

CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1     INTRODUCTION

3.2     BLOCK DIAGRAM OF THE SYSTEM

3.3      CIRCUIT DIAGRAM

3.4      CIRCUIT DESCRIPTION

3.5      SYSTEM OPERATION

3.6      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

An auto turn cutoff charger is an electrical device employed in charging cell phone batteries known as “lithium-ion battery”. This charger automatically shut off the charger through a relay whenever battery attains full charge. This prevents the deep charge of the battery. If the battery voltage is below the set value, then circuit automatically charges the battery.

An Auto cut off battery charger is a good option for people who don’t like having to mess with the battery charging process too much. Simply hook the battery up to an Auto cut off battery charger and it will proceeds to charge our cell phone battery automatically. When the battery is charged it will shut off. Hooking a battery up to an Auto turn off battery charger is really easy too. Simply hook the alligator clips up to the battery posts and leave the Auto turn off battery charger plugged in. A battery will never get overcharged with an Auto turn off battery charger. Many people choose an Auto turn off battery charger over a manual battery charger can fry our batteries by not shutting off when the battery is charger up. This can cause a lot of headaches and prevent us from getting the life expectancy out of the batteries we purchase.

1.2                                                  PROBLEM STATEMENT

In the last decade cellphone battery charger was built only to charge and keep charging the battery even when the battery is fully charged, and this exposes the battery to overcharge and explosion, this can also cause a lot of headaches and prevent us from getting the life expectancy out of the batteries we purchase. To solve this problem, an auto-cutoff of charger was built. With an auto cutoff battery charger, cellphone battery will never get overcharged.

1.3                                        OBJECTIVES OF THE PROJECT

The main aim of this work is to build a charger that will automatically shut off the charger when battery attains full charge. The objectives are:

1. To prevents the deep charge of the battery.
2. To automatically control the charging process of a charger

• To protect the charger from explosion.

1.4                                      SIGNIFICANCE OF THE PROJECT

Building this device will serve as a way of protecting our investment by ensuring that our charger and battery is safe. This study makes it possible for me to learn how to build a charging circuit which is simple, easy to use and components are easily available and at low cost.

1.5                                         APPLICATIONS OF THE PROJECT

This battery charger with little modifications can charge any battery ranging from 0 to 15V. Some of the applications are Rechargeable Cells Motorcycle Batteries Car Batteries, and mobile phone battery.

1.6                                           LIMITATION OF THE PROJECT

Subjecting a discharged cell to a current in the direction which tends to discharge it further to the point the positive and negative terminals switch polarity causes a condition called cell reversal. Generally, pushing current through a discharged cell in this way causes undesirable and irreversible chemical reactions to occur, resulting in permanent damage to the cell. Cell reversal can occur under a number of circumstances, the two most common being:

• When a battery or cell is connected to a charging circuit the wrong way around.
• When a battery made of several cells connected in series is deeply discharged.

In the latter case, the problem occurs due to the different cells in a battery having slightly different capacities. When one cell reaches discharge level ahead of the rest, the remaining cells will force the current through the discharged cell.

Many battery-operated devices have a low-voltage cutoff that prevents deep discharges from occurring that might cause cell reversal.

Cell reversal can occur to a weakly charged cell even before it is fully discharged. If the battery drain current is high enough, the cell’s internal resistance can create a resistive voltage drop that is greater than the cell’s forward emf. This results in the reversal of the cell’s polarity while the current is flowing. The higher the required discharge rate of a battery, the better matched the cells should be, both in the type of cell and state of charge, in order to reduce the chances of cell reversal.

In some situations, such as when correcting Ni-Cad batteries that have been previously overcharged, it may be desirable to fully discharge a battery. To avoid damage from the cell reversal effect, it is necessary to access each cell separately: each cell is individually discharged by connecting a load clip across the terminals of each cell, thereby avoiding cell reversal.

1.7                                         METHODOLOGY

To achieve the aim and objectives of this work, the following are the steps involved:

1. Study of the previous work on the project so as to improve it efficiency.
2. Draw a block diagram.

• Test for continuity of components and devices,

1. Design and calculation for the device was carried out.
2. Studying of various component used in circuit.
3. Construction of the circuit was carried out.

• Finally, the whole device was cased and final test was carried out.

1.8                                                         PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work,   chapter two presents the literature review of the study,  chapter three describes the methods applied,  chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.