Blueprint Design Of A 12 Volt Automatic Battery Charger

ABSTRACT

This project is on a 12volts automatic battery charger with charging progress   and charging level indicator. This work is aimed at building an automatic battery charger which comprises of indicators that indicates charging process and charging level indicator.

Method: The device was first built on a breadboard which is later transfer to vero board and soldered.

Result: The device was completely build and coupled, the result during the test shows that the charger was able to respond to its operation when a 12volts battery was connected it.

Conclusion and Recommendation: At the end of this project – battery charger, this device was built and tested. This type of device is important because there are many rechargeable devices that use 12v battery. I recommend that device should not be used for any other device lower or higher than 12v rating.

CHAPTER ONE

1.0      INTRODUCTION

A battery charger is described as is a device that provides electricity to convert into stored chemical energy for storage in an electrochemical cell by running an electric current through it. [Zhang et al, 2013].

A battery charger consists of a rectifier circuit, power circuit, ripple monitoring, control circuit, regulator circuit.

A Battery charger comes in various designs and voltage.  The choice of a particular charger depends largely on the size of battery. Mini battery charger could be used to charge batteries whose voltage is 12 volts.

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 [Zhang et al, 2013].

This work is aimed at building an automatic battery charger which comprises of indicators that indicates charging process and charging level indicator.

1.2 Background of the Study

Chargers and rechargeable batteries date back to the 1800′s. the concepts and designs have taken on new meaning in the era of portable electronics. With new technology there is charger for almost everything imaginable. The devices are widely used, and their progression over time is huge.

The first battery charger was for the car. The idea came from Gaston Plante, a French physicist that invented the lead acid cell battery in 1859. Though, it was years later that the idea became what it is today, he was the pioneer of the concepts. It was Waldemar Jungner that discovered the Nickel-Cadmium battery in 1899. The Swedish scientist developed this product and it was on the market by 1906. These men of science had ideas before their times. Imagine what they would think of today progress of their once simple ideas.

Chargers for lithium-Ion batteries are almost a necessity in society today. Being used in everything from mobile phones, to laptops, and many other portable devices, they are a must for most. They were introduced in 1991 by Sony. The twenty year phenomenon in the making was originally theorized in the 1970s. Nickel-Metal Hydride was created in the 1980s. This battery comes in all sizes and is probably the most common household battery used today.

Battery charging devices are a common item to own. They come into play with the invention of rechargeable batteries. The idea behind it all was not only to save money but to save time. The average person can save hundreds of dollars per year by using rechargeable batteries with a battery charger. That same person can also save a great deal of time. The more modern designs were also intended to help save the environment by reducing waste and eliminating unnecessary uses of extra energy. The researchers of the pasts would be proud of where the designs have led.

The thought of not having a battery charger for practically everything you own has probably never crossed your mind, but let it for a moment. if you did not have a mobile phone charger or if you weren’t able to recharge those AA batteries for the digital camera what would you do? The concepts may not all have been intended for what they have become, but the transition over time is surely remarkable. Chargers and rechargeable batteries in yesterday’s world are the building blocks for today’s models. So much has developed in the last hundred years in this science. When one looks back at the past and sees what has become, one can help but to think of the future and wonder what will be.

1.2 Project motivation

There is nothing that is as frustrating and dangerous as when a battery is plugged and at the end it was discovered that the battery did not charge. And nothing is as dangerous as when a battery was fully charged and the owner is not aware of the charging state. These are the major problems of the existed battery charger – the inability to display when the charger is charging and to stop charging when fully charged. This study solve problems such as not knowing when a battery is charging and when it is fully charged which can cause the battery not to charged or to over-charge, and which is also cost effective.

1.3 Aim and Objective of Study

The main aim of this work is to build an automatic battery charger which comprises of indicators that indicates charging process and charging level indicator. The objectives are:

1. To build the device
2. To know when a battery is charging or not

• To know the status of a battery thereby saving the battery from over-charge1.4 Significance of Study

Carrying this work will go along way teaching students how battery charger is been made and the operation of battery charger. This study will also be of great benefit to all users of charger and rechargeable devices in that it will help them to understand how their battery is been charged and hw chargers are operated.

1.5 Scope of Study

The scope of this work focuses on the building of a 12v battery that incorporated charging process and charging level indicator. In this work, a voltage sensor circuit is incorporated to sense the voltage of the battery under charge. The charger has the ability to automatically switch OFF when the battery voltage reaches the required optimum level with the help of the contact relay, the transistor and the zener diode when bend the current back to the system, and the system have the ability to indicate when the battery is charging or not, when the battery is empty or fully charged.

1.6  Limitations of Study

This charger can only be used for 12v batteries. The final packaging of the device will compose of three LEDs which includes LED for power, charging process and charging level.

1.7  Definitions of terms

Below are terms that are frequently used in this work and their definitions:

Battery: a container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power.

Charger: a device for charging a battery or battery-powered equipment.

Capacitor – a charge storage device made up of two metallic plates separated by a dielectric, with equal but opposite charges. The AC impedance of a Capacitor is (1 / jWL) and acts as an open circuit in DC applications.

Circuit – a complete path that allows electrical current from one terminal of a voltage source to the other terminal.

Alternating (AC) Current – currents that have a harmonic time dependence.

Ampere (A) – the unit of measurement for electrical current in coulombs per second.