Battery Ignition System, Main Parts, Working, Advantages & Disadvantages

Battery Ignition System is used in automobiles to produce spark in spark plug for combustion of fuel in I.C. engine. Here main source for spark generation is battery. It is used in light vehicles. In this article, we will discuss about Battery Ignition System, main parts, working, advantages and disadvantages.

Main parts of Battery Ignition System

The main parts used in Battery Ignition System have been described in brief below.  Lets us discuss function of each components one by one.


It is a device is used to provide electrical energy for ignition. It is work as storage of energy and charges by dynamo driven by engine. And it converts chemical energy to electric energy. Generally, there are two types of battery used in spark ignition system that is lead acid battery and alkaline battery. First one is used in light duty commercial vehicle and other one is used in heavy duty commercial vehicle.

Ignition Switch

It is a switch which is used to turn ON or OFF ignition system. One end of ignition switch is connected to battery and other with primary winding of ignition coil through ballast resistor. Also you want to know about Difference between Diesel and Petrol Engine

Ballast resistor

It is linked in series with primary winding and it is present in between ignition switch and ignition coil. It is used to prevent injury due to overheating of primary winding of ignition coil. Also, it controls current passes through primary winding and it also made by iron. This Iron will increase electrical resistance fast by raise in heat at certain limit. This additional resistance reduces flow of current which control heat of ignition coil.

Ignition coil

This ignition coil is main part of battery ignition system. And ignition coil act as step transformer and it converts 6 or 12 V of battery into high voltage of 15000 to 30000 V. It consists of magnetic core or soft iron core surrounded by two insulated coil such as primary winding and secondary winding.

Primary winding has 200-300 turn of 20 gauge wires to produce resistance of 1.15 ohm. But secondary winding has 21000 turns of 38-40 gauge wire and it is enough insulated to hold up high voltage. One end of primary winding is linked to battery terminal through ballast resistor and ignition switch. And other end is linked with breaker as well as secondary winding.  This entire unit is enclosed in metal container.

Contact breaker

It is device which is used for making and breaking of primary circuit to ignition coil. And it has two metal points are made up of tungsten and place beside each other. These metal points have 3mm diameter circular flat face. Among two metal points, one is fixed and other is moveable. When points are closed then current flow and when it open, current flow is stopped in ignition coil.


Capacitor is made up of two metal plates separated by air. This capacitor used in ignition system is same to electrical capacitor. It is connected in parallel with contact breaker to prevent damage caused in current and magnetic field. In this way, it facilitates generation of high voltage through ignition coil need for spark.


Distributor is an electrical device used in Battery Ignition System to give out ignition pulses in exact series at time to spark plug.

Spark Plug

This spark plug is used to make sparks to ignite air-fuel mixture in combustion chamber. Each spark plug is attached to distributor of ignition system. Check Brake System Types, Functions, and Types of Brakes in automobile

Working of Battery Ignition System

  • Ignition switch is turned on, current start from battery through ballast register, contact breaker and primary winding.
  • Now this current flowing through primary winding make magnetic field around it. With more current magnetic field will stronger.
  • As contact breaker opens, then current fall down in high voltage induction in secondary winding.
  • This high voltage current produce in secondary winding is transferred to distributor via cable with high tension.
  • Distributor consists of rotor which rotates inside distributor cap and opens contact breaker point. This is because of high current flow to spark plug.
  • Now, spark is generated in engine cylinder by current which make easy combustion of fuel and air.

Advantages of Battery Ignition System

  • Good spark at low engine speed and better starting than magneto system
  • Low maintenance cost
  • No problems due to adjustment of spark timings
  • More fuel efficiency

Disadvantages of Battery Ignition System

  • Battery need monthly maintenance
  • In case of battery go wrong, engine cannot be started.