CHAPTER ONE INTRODUCTION
Battery charger is a device that charges or recharges or current back through lead – acid cell, Alkaline cell, carbon zinc cell and nicad batteries, reversing chemical action of discharging of the battery.
In 1968 Makita Charles invented Battery charger called Makita charger. This specified for cordless tool like above batteries. This charger was designed to provide rapid recovery time, vital for quick recharge. It has frequent starts and stops. He achieved this when he integrated the following electrical and electronics parts together: Transformer, Diodes, Resistors, capacitor, wire and integrated circuit all connected on the veroboard and cased with electric conducting material. Including other peripherals that made the device heavy and costly.
In 1972 Saitek Smart invented Battery charger called Saitek Smart charger. This was regarded as the fastest model on the market, the smart charger is for smart charging. Smart charger is specifically designed to deliver ultra fast charging, conditioning and checking with a large liquid crystal display (LCD) panel that keeps users fully informed of charging status and batter condition. The Smart charger’s logic recognized battery types and monitors the charging process. Bad batteries are automatically rejected. Easy to use. Just insert batteries and close the lid. The above qualities make Saitek smart charger the model battery charger in the market. It costs U.S. $79.95 which rates N7595.25 in Nigeria.
The aim of this work is to design and construct a lesscost, light-weight and wood casing device that will charge or recharge or force current backward through lead-acid cells when they are discharged and such device is called battery charger.”
The battery charger sold at market produced by first inventors like Makita Charles in 1908 and Saitek Smart in 1972 are very costly. And not only costly but the casing material were made of electric conducting w metal that can electrocute some body. It is heavy.
In this case, lesscost, lightweight and wood casing battery charger needs to be designed and constructed for poor and developing country like Nigeria.
DEVELOPMENT OF THE CELL
Since battery charger, charges batteries most especially lead-acid batteries the knowledge about batteries should not be left out.
The ancient Persians made an electric cell that consists of copper electrode at the bottom of a jar and an iron electrode protruding down through an insulating stopper and oxidation – reduction potential of – 0.337V. Iron develops o.44V. the difference between these two metals in the same electrolyte is about 0.777V. However, the electrolyte helped to determine the actual voltage developed between the two electrodes. This is the basic idea of a battery-two dissimilar metal electrode in some kind of in electrolyte. The cell produces an emf until the chemical action is complete.
In 1800 and Italian Scientist Volta, developed a cell using silver and zinc electrolyte. In 1966 a French scientist lechlanche developed the 1 – 5V dry cell. The electrodes are zinc for the negative pole and manganese dioxide for positive pole, with an electrolyte of moist ammonium and zinc chloride salt. Rechargeable batteries were developed in the late 1800S.
In 1947 the mercury cell, another so called dry, cell was invented. The usual method of categorizing the different types of cell is to list them as primary secondary and other types.
Primary cell can not be recharged.
Secondary cells can be recharged.
Other cells such as high sensitivity photoelectric, solar nuclear and fuel do not fit in either of these categories.
In charging batteries, the cells are connected in series so that each cell receives the same charging current.
If the cells are connected in parallel, it would be difficult to maintain the same amount of current in the cell.
From the above battery types, the example of primary cell is lechlanche cell with active materials of zinc the negative pole and zinc chloride or ammonium chloride the electrolyte.
The secondary cell is lead-acid cell. The active materials are metallic lead the negative plate, lead dioxide the positive plate and dilute hydrogen tetraoxosulphate III acid the electrolyte.
Since a weak battery needs a device that will reverse the chemical action of it, there is no need to throw away weak or rundown battery battery charger recharges the battery and thereby makes the battery to returns its capacity again.
LIMITATION OF THE STUDY
This research work was limited by time and finance. It was not easy for the researcher to carryout the research within the time limited. Also the finance needed to back up the project and the research work is too much, there by possessing an obstruction to the effective work done.