What are Halogen Bulbs?

Halogen headlight bulbs can be found on approximately 85% of the cars on the road today, they are the most popular type of headlight option on the market today mainly because they are cheap to manufacture and cheap to replace.

Typically, they emit a bright yellow /white light and can last up to one thousand hours but tend to last longer due to usage patterns.

How do halogen bulbs work?

Halogen bulbs are generally made up of four elements:

1. A tungsten filament.
2. Inert gas e.g. Argon or nitrogen to prevent oxidation of the tungsten filament.
3. Halogen gas via Iodine or bromine which give the bulb a higher intensity / brightness.
4. Glass capsule which envelopes the other components.

Electricity passes through the tungsten filament which is heated up to 2,500° Celsius which then starts to glow, the gas within in the bulb is resistant to extreme high temperatures.

What are Xenon / HID bulbs?

High intensity discharge (HID) have been popular since their introduction on high end luxury cars in the 1990’s, but are now more common place.

Xenon lights are up to 3 times brighter than halogen bulbs and can last up to 2,500 hours but tend to last longer due to usage patterns.

They are more energy efficient compared to halogen bulbs.

How do Xenon / HID bulbs work?

High voltage passes current through two opposing electrodes that ionizes the xenon gas in the glass capsule thereby creating an arc.

The temperature within the capsule rises quickly ionising the gas mixture lowering the resistance between the two electrodes.

The ballast then constantly provides the bulb with constant high power ensuring that the bulb is up to operating temperature – this can take a few seconds and is noticeable when the lights are turned on and get brighter gradually.

HID's stand for High Intensity Discharge

High-intensity discharge lamps (HID lamps) are a type of electrical gas-discharge lamp which produce light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube.

 LED  - Light Emitting Diode

LED headlights generate illumination by passing an electric current through miniature semiconductors that release photons. This electrical phenomenon is responsible for illuminating the path in front. LED headlights emit an exceptionally luminous white light.

Advantages.

Firstly, they consume lower power compared to traditional halogen bulbs, making them more energy-efficient.

This not only reduces strain on the car's electrical system but also improves fuel economy, which is particularly beneficial for electric vehicles.

Additionally, LED headlights emit a very bright beam of light, providing excellent visibility on the road. Their advanced technology allows for more precise and adaptive headlight control, offering enhanced safety.

Lastly, LED headlights have a longer lifespan, reducing the frequency of replacements. However, there are a few drawbacks to consider.

Disadvantages.

LED headlights can dazzle oncoming traffic if not properly adjusted, potentially causing discomfort or temporary blindness. The benefits of LED headlights outweigh the drawbacks, making them a popular choice for many drivers.

Are they Legal to use for headlights?

Not legally in the UK. There are many aftermarket suppliers offering LED headlight replacement kits for cars with halogen lights (a kit is required as power and cooling differences between the bulb types mean you can’t just swap bulbs), but unfortunately it is not legal to make this upgrade due to legislation that does not provide a certification process for aftermarket LED headlights. BUT currently a lot of people are pushing back on this and in time there may be change, we will keep you posted.

High voltage passes current through two opposing electrodes that ionizes the xenon gas in the glass capsule thereby creating an arc.

The temperature within the capsule rises quickly ionizing the gas mixture lowering the resistance between the two electrodes.

 The ballast then constantly provides the bulb with constant high power ensuring that the bulb is up to operating temperature – this can take a few seconds and is noticeable when the lights are turned on and get brighter gradually.

The tungsten filament in the halogen bulb can and does burn out.

HID’s do not have a tungsten filament like that of a halogen bulb.

Since HID’s do not have a tungsten filament they can last up to 3000 hours as opposed to a halogen bulb which can last between 450 – 1000 hours.

The reality is that both types bulbs can and often do technically last longer providing that there is a stable power supply (meaning your electrics are good!) and also how often they are used.

 Brighter and better.

• Xenon  / HID bulbs are up to 300% brighter than halogens bulbs.
• They can last up to 10 times longer than halogen bulbs.
• Xenon/HID bulbs produce a crisper, cleaner and brighter light in comparison to halogen bulbs resulting in more usable light.
• Lower power consumption (35W) compared to halogen bulbs (typically 55W).

 

HID / Xenon lights are safer as they give a wider and deeper field of view, making them far more superior to halogen bulbs.

 

The 'K' denotes Kelvin, which is the primary unit of temperature measurement in physical sciences, in this instance the 'colour temperature'.

4300k - This is usually the factory fitted xenon bulb specification and is described as a warm white colour, most household fluorescent are accepted to be at the 4300k - 4500k mark.

6000k  - This is considered to be the most optimum colour for road usage and aesthetics, this colour omits a brilliant white light (ice white) and is best described as 'noon sunlight'.

8000k - This shade gives more blue overtones, it omits a more blue light which can be described as shaded skylight. This colour is less effective in terms of visibility than both 4300k and 6000k.

10000k - Like the 8000k but a darker shade of blue. This shade gives you less usable light.

 

HID's stand for High Intensity Discharge

High-intensity discharge lamps (HID lamps) are a type of electrical gas-discharge lamp which produce light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube.

​This is a rather grey area.

Depending on where you look or ask you will receive different answers.

Here’s what we know:

 

The guidelines state that vehicles fitted with xenons may have a self-leveling system and a headlamp washer system.

The key word being ‘may’ and this is widely open to interpretation.

We found that if you use reasonable kelvin range (4300k -6000k) it generally causes less issues with other road users.

It is generally accepted that officially HID's are not road legal.

MOT Failure.

Providing your beam pattern is aligned there is nothing to worry about, however some testing centers will check for self-leveling systems and washer systems.

If you have a reflector lens you should be using anti-glare bulbs if possible (all of our H7 bulbs are anti-glare by default and work just as fine in projector lenses).

We have supplied many clients around the globe and closer to home, we have supplied our very own boys and girls in blue (their private cars) and if its good enough for them…

The ballast does not determine the colour of the bulb?

It is advisable to have the same model of ballasts fitted to the vehicle.

If two different types of ballasts are fitted to the vehicle the bulbs may power up differently and may actually emit different shades of light.

A Bi-Xenon bulb is where both the dipped beam and the high beam are all in one bulb.

A H4 bi-xenon bulb will contain both the dip beam and the high beam.

So whats the difference between a projector and reflector lens?

The projector lens has a glass sphere inside which the bulb sits. You cannot see your dipped beam bulb inside the sphere housing.

 

With the reflector lens you can see the bulb within the housing. The beam pattern comes from the shiny reflector element that the bulb sits in front of and is surrounded by.