How to choose the proper LED Retrofit (LED sets)?

Burning out bulbs is a common problem for many drivers. This is why LED retrofits are becoming increasingly popular on the market. In short - retrofits are equivalents of halogen bulbs, in which the filament and glass bulb have been replaced by a more efficient LED. Leaving the cap fixed, as well as similar shape, allow to mount them directly in the factory headlights. Manufacturers of LED retrofit are introducing more and more new solutions in this segment. They are much more durable than traditional bulbs and at the same time provide a modern look. It is worth emphasising that LED technology has many advantages and greater possibilities than traditional incandescent lighting. Below I will try to answer the question of what features should be taken into account when choosing this type of solution. The most important factors in choosing LED retrofits are light efficiency, size and type of cooling. This has been known for a long time by the best automotive manufacturers, in whose offer retrofits occupy an increasingly important place.

Firstly, the luminous flux…

The most important feature to pay attention to when choosing LED retrofits as a replacement for traditional lighting are the light sources used, which have a direct impact on the luminous flux. Until recently, the main source of light was a tungsten filament bulb. Currently, on the roads we can increasingly see cars equipped with xenon and LED lighting, which is characterised by much better performance, which directly affects the safety of driving.

Three basic LED sources for retrofits can be distinguished: COB, SMD and CSP. Leading manufacturers have long turned to SMD and CSP technology, which allows to obtain the best efficiency from 1W, giving a significant advantage over other solutions. LED retrofits, which use branded diodes used in OEM (HP - High Power) production, slowly start to appear on the market. Thanks to such a solution, we can obtain a much stronger luminous flux and a guarantee of the highest quality and longevity.

The placement of the diode itself and its surface is also very important. It should be noted whether the diodes are placed in a place similar to that of a traditional tungsten filament (the so-called twisted pair). If the diodes are placed too far in front or behind, the light beam will not be fully directed onto the road. Too large surface of the diode, contrary to appearances, may be a disadvantage. Such a solution makes the luminous flux stronger but less effective. Only a small part of the light coming out from the headlight falls in front of the car, in a place where the light beam should be the strongest and most effective.

Secondly, the size…

A very important element when choosing LED replacements for traditional light sources found in cars is size, although I don’t even know if it is the most important. In many models of cars, replacing a passing light bulb, e.g. H7, is not that easy. Everyone who has had the pleasure of experiencing this at least once knows about it. This difficulty is primarily due to the amount of space available under the hood. Often there is so little space around the headlight that it is difficult to fit your hand. This is why it is so important that the retrofit is as small as possible. First of all, it should be noted that the length of the LED burner should be as close as possible to the classic bulb. This will help us avoid problems and unpleasant surprises during installation. The pole on which the diodes are mounted should be similar in size to a traditional glass bulb. It is also worth paying attention to the size of the heatsink discharging heat from the diode, protecting the burner itself from overheating. It should not take up too much space behind the burner itself. Additionally, its diameter should not exceed 40mm (diameter of the H4 bulb flange). It is not uncommon for something as trivial as changing a light bulb to require removal of the bumper.

Thirdly, cooling…

There are two basic types of cooling on the market: active and passive. We will start with the latter. Passive cooling is characterized by the fact that heat dissipation takes place by means of a heat sink without moving parts. Passive cooling can be found in the form of a classic heatsink in the form of a ribbed structure or aluminium pips. The disadvantage of this type of solution is the size of the heatsink, which in a passive way must carry away the heat from the diode. Unfortunately, it often happens that there is not enough space to mount it. A small size passive cooling heatsink may be associated with rapid overheating and burning of the diode.

Active cooling is characterized by the fact that the heat is dissipated by a moving part such as a fan. In view of the fact that heat dissipation is a key issue with regard to service life, companies on the market use Japanese bearings to prevent rapid wear.

It is also worth paying attention to the materials used in production. In the case of passive cooling, it is good that the heatsink is made of a material that dissipates the heat in the best possible way (e.g. copper alloy). In case of active cooling, the most important part is the fan; therefore, there are already LED retrofits on the market, in which the cooling element has been equipped, among others, with a Japanese bearing preventing quick wear and tear.

In summary, the product features presented above are of major importance when choosing the right LED retrofit for lighting conversion. On the market, the offer of products in this group is very wide, both in terms of the light source used (type of LED), size and form and type of cooling. Therefore, before making the final decision it is worth considering what criteria should be met by the LED set to avoid problems with e.g. its installation. However, it does not change the fact that the luminous flux, size and type of cooling have a direct impact on comfort and safety on the road.

Bartłomiej Szternal
Product Manager