Battery Ignition System: Definition and Working

What is Battery Ignition System?

A battery ignition system has a 6- or 12-volt battery charged by an engine-driven generator to supply electricity, an ignition coil to increase the voltage, a device to interrupt current from the coil, a distributor to direct current to the correct cylinder, and a spark plug projecting into each cylinder.

Current goes from the battery through the primary winding of the coil, through the interrupting device, and back to the battery.

Parts of Battery Ignition System:

The main components of Battery Ignition system are listed below:

  • Ignition switch
  • Battery
  • Ignition coil
  • Ballast resistor
  • Contact breaker
  • Distributor
  • Capacitor
  • Spark Plug

Ignition Switch

It is used for ON or OFF the engine. One end of the switch is connected with the Primary Winding of the Ignition Coil via Ballast Resistor, and another end is connected with the Battery.

Basically, when the key is put inside it and turned the switch in ON position then the circuit is completed (Close Circuit), and when moved towards the OFF position than its work as an open circuit. Nowadays, this switch is replaced by the Push Button, and this system is called a keyless system.

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Battery Ignition System


The battery is provided for supply the initial current to the ignition system more specifically ignition coil. Generally, the voltage of the battery is 6V or 12V or 24 V. In an automobile there are two types of Battery use widely, one is lead-acid battery and another one is the alkaline battery. Although there are Zinc Acid Battery and Lithium-Ion Battery is used in modern vehicles.

Ignition coil

It is the main junction or you can say the main part of Battery Ignition System. The main purpose of it is to step up battery voltage so that it is sufficient for generates the spark.

It is working as a step-up transformer, and have two winds, one is primary which have a lesser turn, and the other one is secondary which have a higher number of turns.

Ballast resistor

This is used to limit the current in the ignition circuit and generally made of Iron. It is placed in series between the Ignition Switch and Ignition Coil. However, it is used in old automobile vehicles.

Contact Breaker

The contact breaker is an electrical switch which is regulated by the cam and when the breaker is open, current flows through the condenser and charges it.


It is used in the multi-cylinder engine, and its purpose is to regulate spark in each spark plug at the correct sequence.

There are two types of distributors.

  • Carbon Brush Type: It is consisting of Carbon Brush which is slides over the metallic section embedded in the distributor cap.
  • Gap Type: In this type, the rotor arm is passed through the metallic section of the distributor cap but it does not touch the surface of the distributor cap. that’s why it is called Gap Type Distributor.


A capacitor is a storing device where electrical energy is stored. It is fitted parallel to the contact breaker, when the current drops then it supplied the additional current so that the spark is produced. It is made of two metal plates separated by air or any other insulating material.

Spark Plug

Spark Plug is another important part of the Battery Ignition system. Here the actual Spark is generated for the combustion of Fuel or Charge. If there is more than one spark plug that exists then each one is connected separately with the distributor and gives the spark in the sequence.

Working of Battery Ignition System:

In Battery Ignition System, when the Ignition Switch is turned on then the current will flow to the primary circuit through ballast register, primary winding and contact breaker

The flowing current induced a magnetic field around the primary winding, the more current we supply the more magnetic field will generate. At a certain time, the contact breaker opens the current is flowing through the primary winding and fall. This sudden fall of current generates very high voltage around 300 V in the primary winding section.

Due to this immense amount of voltage the capacitor comes into the charging state when the capacitor charged fully then it starts delivering the current towards the battery, due to this reverse flowing of the current and already induced magnetic field in the primary winding, a very high voltage of 15000 V to 30000 V is generated in the secondary winding.

This high voltage current then transferred to the distributor via high tension cable, where already a rotor rotates inside the distributor cap and has metallic segments embedded on it. So when its start rotating then at a certain stage it opens the contact breaker point which allows the high voltage current to transferred to the spark plugs through the metallic segments.

So, when the high voltage current reaches the spark plug then its generates a high intensity of spark inside the engine cylinder, which allows the combustion fuel to burn.

Advantages of Battery Ignition System:

These are the following advantages of Battery Ignition System:

  • The intensity of the spark is good.
  • It can also provide a high concentration of spark even in low engine speed or starting of Engine.
  • The maintenance of this ignition system is very less compared to others.

Disadvantages of Battery Ignition System:

  • Efficiency decreased with a reduction in spark intensity.
  • Occupies more space.
  • Efficiency decreased with a reduction in spark intensity.
  • Need periodic maintenance is needed for Battery only.

Applications of Battery Ignition System:

Battery Ignition System is used in Automobile (Car, Bus, Truck even in the Bike) to produce the Spark so that Combustion fuel can be burned.