Battery Ignition System Parts And Functions (Full Explained)

Battery ignition system or some call the conventional ignition system is one of many type of ignition system that is widely applied to used cars. But now, the ignition system has changed to full electronic.

However, the basis of an electronic ignition system comes from a battery ignition system.

Therefore, as car enthusiasts, we must keep learning how the battery ignition system works because it is the basis.

We have discussed the article about battery ignition system in the following link; Easy to understand, Battery ignition system working principle

In this article, we will focus on discussing the components of the battery ignition system and each function.

Battery ignition system components consist of;

  • Battery
  • Ignition switch
  • Ballast resistor
  • Ignition coil
  • Contact breaker
  • Capacitor
  • Distributor
  • Spark plug
  • High voltage wire

1. Battery

As the name suggests, the battery is a main part of the battery ignition system. The function of the battery in this system, is as a power source.

Basically, sparks on spark plugs occur as a result of electron jumps with very high voltages. so the source of energy, is electrical energy derived from vehicle batteries.

Generally for passenger vehicles (MPV, SUV) use 12 V batteries.

2. Ignition switch

Ignition switch is a part to manually activate or deactivate the ignition system of the vehicle.

Called manually because we control it.

In the past, the ignition switch was still in mechanical form using plate connections. To activate it, we need to enter the vehicle key and turn it to the ON position.

But now, there is a keyless technology where we do not need to enter the vehicle key into the ignition switch.

However, that does not mean the car now does not include ignition switches. Ignition switches remain only in a more electric form.

3. Ballast resistor

Is a resistor with a high resistance level, its function is to regulate the current that flow to the ignition coil.

What is the purpose?

In general, there are two objectives, to launch better starting system, and to avoid hot temperatures of ignition coil.

During the starting process, the starter motor requires a large amount of current to turn the engine crankshaft. At the same time, the ignition system is active. If there is no resistor, more electric current will enter the ignition coil than the starter motor.

Because the ignition coil has smaller load than the starter motor load so naturally the electric current will flow more to the smaller load.

To avoid this, a high resistance resistor is placed to limit the amount of current entering the ignition coil, so that the starter motor can work stronger.

In addition to the starting process, the electric current can also affect the ignition coil temperature. Large currents cause high ignition coil temperatures, while high temperatures can reduce electromagnetic induction.

Therefore, the ballast resistor also serves to maintain the ignition coil temperature so that it is not too hot.

4. Ignition coil

Is a step up transformer which function is to increase the voltage. The working principle of the ignition coil is also the same as a transformer that uses two coils with different number of turns.

But the thing that make it different is, the primary coil is located on the outside while the secondary coil is located on the inside.

Then how does electromagnetic induction take place?

It turns out that induction occurs when the electric current in the primary coil is cut off. The process is like this, when the current in the primary coil is still connected, magnetic fields appear around the primary coil. When the primary coil current is suddenly cut off, the magnetic field moves inside before finally disappearing.

When the magnetic field moves rapidly inside of the secondary coil, that's when electromagnetic induction occurs.

The article about ignition coil will be full explained on this article How does ignition coil works ?.

5. contact breaker / breaker point

It is a mechanism to disconnecting and connecting current on the primary coil quickly and precisely.

In this mechanism there are three main components, namely cam breaker, arm breaker and breaker point.

Contact breakers work mechanically, using two contacts. When these two contacts are connected, the primary coil current is also connected. But when these two contacts are separated, the primary coil current is also separated.

The component for separating contact breakers is cam breakers. Cam breaker consists of cam which can bring up the breaker arm. When the breaker arm is raised, the contact will separated. Conversely, when the cam shifts, the contacts are connected again.

6. Capacitor

Serves to prevent splashes in the contact breaker.

Although it is not a main part, capacitors greatly affect the performance of the ignition system. Because when there is a spark on the contact breaker, the primary current is not cut off so there is no induction in the ignition coil.

In fact, the breaker contact gap is so small that a spark could appear even though it is only 12 V.

To prevent this, the capacitor is located after the breaker point and before the ground. Capacitor is an electronic component that is able to store a little electricity and immediately release it when the current source is stop.

When the contact breaker is still connected, the capacitor will store current, when the breaker contact is broken the capacitor will release an electric current (discharge) so there is no potential difference in the two contacts.

That is why there is no spark.

7. Distributor

Is a component for distributing the ignition coil output (secondary coil) to each spark plug with the appropriate firing order.

You can only find distributors on engine that have more than one cylinder such as a car. While for single cylinder engines such as motorcycle, there are no distributors.

8. Spark plug

Spark plugs are components for converting electrical energy into sparks.

How did it happen?

Spark plug uses the air gap principle that utilizes the potential difference between the electrode (+) and ground (-). So when high-voltage electricity reaches the spark plug electrode, the electron automatically jumps to the ground because the higher the voltage, the higher the potential difference.

The higher the potential difference, the stronger the electron's movement.

Actually the electron jump is not a fire, but just a flash of electricity. but also has a burning effect, so it can be used for combustion.

9. High voltage wire

It is a special cable used to carry 20,000 V electrical energy from the ignition coil to the spark plug.

The diameter of this cable is quite large, sometimes when we touch the cable insulator, we can be electrocuted even though not dangerous. That shows how high the voltage of this spark plug wire.