CHAPTER ONE
INTRODUCTION
1.1    Background to the study
Sprayers are devices that are specially designed to spray liquid quickly and easily. They come in a number of different varieties. A sprayer is used to cover large area such as lawns quickly and easily. A boom sprayer of this type is typically used for spraying chemicals such as pesticides, herbicides, herbicides, insecticides and fungicides.
Along with proper plant selection and cure, controlling pests in lawn or garden is an important part of maintenance. Pesticide, insecticides, herbicides and fungicides should be limited where possible, but when necessary, they should be used responsibility. This is the major reason why crop protection is highly required by dealing with the destructive agents that that usually attack crops as: weeds, pests, insect, diseases e.t.c.
In the dynamic and post changing agricultural system of the country, especially diversification in the dropping particle and commercialization of agriculture, more equipments are required. The existing boom sprayer is operated by tractor.
Hence a battery operated solar charged boom sprayer is to be designed with a low weight compared with the existing boom sprayer which is operated by a tractor.
1.2    Solar Energy and Deep Cycle Battery
1.2.1    Solar Energy   
From time immemorial, the sun has been the prime source of energy for life on earth. The solar energy is being used directly for purposes like drying curing agricultural produce, preserving food produce e.t.c.
Today the energy we derive from fuel-wood, petroleum, paraffin, hydro-electricity and foods originates indirectly from sun.
Solar energy is virtually inexhaustible. The total energy we receive from the sun far exceeds our energy demands. It is probably the most reliable source of energy available everywhere and to everyone, unlike other sources.
Ever since the industrial revolutions, human have been dependent on fuels, electricity and wind energy for development in many countries. There are various research work going on about solar energy.
Electricity can be converted from sunlight into direct current with the use of photovoltaic cell (PV). A photovoltaic cell is a device that converts sunlight into direct current using the photovoltaic effect.
1.2.2    Deep Cycle Battery
Batteries are the key component in various type of renewable energy systems that require the storage of electricity. A battery is essentially a storage vessel for electricity. It is a critical component heavily relied upon by the system as a whole. A battery bank can provide a relatively constant source of power when the grid is down, or during period when your photovoltaic system is not producing power. Although batteries are not one hundred percent efficient, they are predictable and stable enough for reliable long-term service. Batteries are basically the only method to store direct current (DC) power produced from source like solar panel, wind generators, micro-hydro or generators.
Deep Cycle Batteries are energy storage units or device in which a chemical reaction occurs that develops voltage and results in electricity. These batteries are designed to be cycled (discharged and recharged) many times.  While a car battery is designed to deliver a burst of energy for a short time, a deep cycle battery provides power at a steady rate over a long period of time.
There are different types of deep cycle batteries such as; Flooded batteries, gel batteries, and AGM batteries (Absorbed Glass Mat); And more recently, Lithium – ion. All are made differently.