To make an HID system operate, a high-voltage pulse must be transmitted to the HID bulb. That’s where ballasts come in. An HID ballast creates, drives and sustains the electrical arc in a bulb which maintains the light current in your car’s headlights. It’s a complex circuit made up of many components, each one tasked with carrying out a specific function. Needless to say, this is a hefty task that requires countless car parts to work together in perfect symphony.

Kensun, Inc. offers both 35W and 55W ballasts. We wanted to provide you with some background information on the different choices of wattage to help you choose the right ballasts for you and your car.

One fact to keep abreast of is that while no electrical device provides 100% efficiency, (some power is invariably lost as heat, which happens to be the reason ballasts warm up during operation) we have succeeded in reaching efficiency levels of nearly 90%. This means that if your input a total of 10W, the result will be a light beam of 9W.

The rule is: the higher the power level, the more heat. But then you also have what’s called the “law of diminishing returns.” If you increase power by one watt, you get an additional 20 lumens, but adding another watt will only result in a increase of 19 lumens. So it would seem that while 55W ballasts produce greater power, they are less efficient than their 35W counterparts.

Another issue with higher-power ballasts is that since they produce greater heat levels and warm up faster, they need to be mounted on an area with good ventilation. This requires more work and some level of oversight. To complicate matters, factory wiring is usually designed to allow a stream of 16-55 watts of energy, and a higher power source may cause damage to this network. A relay harness may help avoid overloading the electric system. It allows HID bulbs and ballasts to operate independently of the vehicle’s original wiring system and can provide a power source that is more consistent.

55W ballasts should only be installed alongside 55W bulbs since you run the risk of running down 35W ballasts much faster if they’re powered by a higher power source.

To sum things up, a greater power source will result in brighter light, but the flipside is that it comes with a number of technical deficiencies that may end up making the process of installing and maintaining 55W more troublesome over extended periods of time.