Page 66 - Electrician - TT (Volume 1)

ELECTRICIAN - CITS

Battery
Battery is a collection of cells that converts chemical energy into electrical energy.
Symbol

Classification of cellbased on the electrolyte
1 Wet Cell

2 Drycell
Based on the electrical properties
1 Primary Cell
2 Secondary Cell
3 Reserve Cell

4 Fuel Cell
Wet cell
It is an electric cell in which the electrolyte is in the form of liquid. The other name of this cell is flooded cell .This
cells must be operated in an upright position Wet cells were a precursor to dry cells and are commonly used as a
learning tool for electrochemistry.
Dry cell
Dry cell is a cell in which the electrolyte exists in the form of paste, with only enough moisture to allow current to
flow.
Primary cell
These are cell, it converts chemical energy into electrical energy and cannot be rechargeable. Primary batteries
are designed to be used until exhausted of energy then discarded. Their chemical reactions are generally not
reversible, so they cannot be recharged. When the supply of reactants in the battery is exhausted, the battery
stops producing current and is useless
Secondary cell
The cell that can be recharge by sending electric current in reverse direction to that of discharging.Secondary
batteries can be recharged; that is, they can have their chemical reactions reversed by applying electric current
to the cell. This regenerates the original chemical reactants, so they can be used, recharged, and used again
multiple times
Reserve cell
It is also called standby battery. It is a primary battery where part is isolated until the battery needs to be used.
A reserve battery can be stored unassembled (inactivated and supplying no power) for a long period (perhaps
years). When the battery is needed, then it is assembled (e.g., by adding electrolyte); once assembled, the battery
is charged and ready to work.
Uses: Used in Missiles, Bomb, Various weapon systems etc.
Fuel cell
Device that converts the chemical energy from a fuel into electricity through a chemical reaction of +vely charged
hydrogen ions with oxygen or another oxidising agent.
Uses: Used in Satellite, Space capsule etc.
Types of primary cell

• Voltaic cell.
• Carbon-zinc cell (Leclanche cell or Dry cell)

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CITS : Power - Electrician & Wireman - Lesson 13-19 CITS : Power - Electrician & Wireman - Lesson 13-19