Since HID light came into being, it has pass different judgements ont it. Its strong lighting ability significantly reduces the dangers of driving at night, but those not-well-designed products poses a serious threat to cars coming in the opposite direction. Color temperature decline, defect rate, short life expectancy, are most common complained problems by end-users on the internet. Therefore, we will tell you honestly what are the real causes of these shortcomings.
 
Serious glaring problems are in fact the manufacturer's fault

      Many people are talking on the internet that they are completely made invisible by HID light of the vehicles coming in the opposite direction. I had a similar experience as well, but why the HID light originally came with the vehicles, such as BMW, BENZ does not have this problem? The original HID light do not have glaring, and even the lighting range and brightness are higher than those sold on the market. This is not only because of the HID lamp design difference from the halogen designs, but also, and more importantly, because the HID KITS manufacturer simply does not do a good job on product quality control.

      HID and halogen bulbs have different "light-model", probably we all heard about this, because halogen bulb burns the tungsten to produce light, while the HID light is based on high voltaic jumping between the bulb’s positive and negetive to arcing the "iodide" to produce light. The halogen bulb is designed to be straight coil-shaped tungsten wire; and the HID bulb will show a curved arc state (light-emitting height there will be 0.5mm
more). The evenness of light and color temperature is very different for the 2 kinds of light. The light by burning the tungsten is around 3000K yellow light. But the light given off at the top of HID lamp is a high color temperature white, and the light given off at the bottom due to going through more halogen gas is low-temperature yellow color.

      Although both types are different light, if the bulb optical axis positioning is correct, converted HID glaring rate will be reduced to “acceptable range” only if the bulb optical axis to be accurately installed on the light-emitting center.

      No scientific basis for-- the higher color temperature, the better lighting effect  

     First of all, the HID bulb with high color temperature has a relatively short product life,. 4300K bulb life is 3200 hours, 5100K and 6000K bulb is about 2000 hours, but the color temperature up to 10000K bulb, has been ascertained that no lifetime data available (because the bulb manufacturer does not provide any), but according to previous data, the life of such bulbs should be only 1 / 2 of those standard products (because 10000K bulbs have a very high internal pressure).

      Use halogen bulbs for example, the illumination is about 1450Lm (lumens), 4300K bulbs 3200Lm, 5100K bulbs 2700Lm, 6000k bulb is about 2500Lm, but the 10000K bulb illumination is only 2000Lm. 40% less than the 4300K light bulb.

      In addition to the insufficient brightness, the penetration is also a problem. The visible light wavelength for human eyes is around 380nm (violet) ~ 770nm (red). The shorter wavelengths of light, the worse of its penetration, the more difficult to penetrate the water vapor or mist, and easer to be prone to the phenomenon of refraction! In some cases that the, "extra-bright bulbs” appear to be no light in the rainy night, and this is because the light has been refracted by the water on the road.

      Replacement of the higher color temperature of HID will only results in worse lighting in the rainy day!

Different lifetime: by constant current or constant power.
       People buy HID bulbs and often come across problems such as bulb failure ballast burning. These problems may be caused by the poor quality of the products, but more likely, the fact is the ballast design concept is completely wrong! At present there are two kinds of ballast design concepts, namely, constant current and constant power, constant power is the correct design to ensure long life of HID.
      For new HID bulbs, the distance between electrodes is 4.2mm . To generate the high voltaic jumping between the bulb’s positive and negetive, there must be a 23000V added at both ends of the electrode (the voltage will be reduced to 85 ± 17V after startup). But with the lighting frequency, time increases, the distance between the two electrodes will be more and more far away, and the working voltage will gradually increase from 85V to 102V.

      High and low working voltage of the light bulb color does not determine by the color temperature. Factors affecting color temperature are the filling metal halide within the bulb, and also the pressure of the filling gas (the higher the color temperature, the higher the pressure)

        Ballast designed by constant current will continue to supply a stable operating current, but with the HID tube pressure increases, the overall output power (according to the formula P = VI we can see) will also gradually increase by the rated 35W to 40W or even 45W! Additional power can easily damage the molten lead bulb mounts, and in many cases the ballast and the bulbs will be destroyed! The ballast designed by constant power will not have such concerns, computing circuits will lower the output current as the tube pressure increases, so that the power consumption of the entire system can be maintained at 35W. Du Peng electronics designs and produces its own brand DOOP HID conversion kit is using constant power design and concept.