Tech Talk: Motorcycle Lighting Part 1 – Headlight & Fog Lights

This write-up is part of a series on LED lighting. Most of the content is this series is applicable to most motorcycles, even though some references are specific to Kawasaki’s Versys-X. You can read the other write-ups here:


In an effort to keep the cost down, Kawasaki used incandescent light bulbs on the Versys-X (bar the optional LED fog lights). The headlight is a simple reflector unit with an H4 halogen bulb. Its light output is nothing to write home about. Despite running the OE fog lights, I was still yearning for more light output.

I have always liked simple, non-evasive mods, especially when it comes to electrics. If you’ve ever needed to troubleshoot electrical gremlins, you know what I am talking about. The easiest solution is to drop in an H4 LED bulb. LED bulbs have several advantages over traditional halogen bulbs: higher light output, lower power consumption, and supposedly a longer lifespan.

More often than not, people are retrofitting an LED bulb in a housing that was designed for halogen bulbs. Therefore, the pitfall is in the overall design of the bulb. A badly designed LED bulbs will produce a lot scatter, blinding oncoming traffic. And so I set forth my search with the following requirements:

  • Plug and plug (H4 compatible, high/low beam)
  • Clean beam pattern
  • < 30W power consumption
  • Passive cooling

Note: You can choose between bulbs with active (fan) or passive (fanless) cooling. I feel that “fanless” bulbs are the better choice. Bulbs with active cooling use smaller heatsinks. As a result, the LED chip will overheat as soon as the fan dies. More often than not, these fans use unreliable sleeve bearings. Especially on a bike, the fan will be subject to lots of dust and heat, resulting in causing premature failure.

In Search of the Holy Grail

When it comes to LED lighting, the sheer amount of available products is overwhelming. Shortlisting your requirements allows you to narrow down your search results. I had chosen a handful of bulbs with passive cooling and started looking for reviews. I was especially interested in a bulb from a brand called “HLXG”. Unfortunately, it’s hard to find any kind of meaningful information about products on AliExpress, besides promotional materials. Luckily, I caught a break and found a video uploaded by a bloke called Dawid. In his video, he compares 3 LED bulbs from AliExpress.

Courtesy of “Dawid&Marta’s Moto Adventures”

The HLXG bulbs came out as the winner. I especially like the fact that this bulbs only consumes 18W (3 times less than its halogen counterpart). Since it only consumes 18W, I assume it also generates less heat. If you’re interested in this bulb, you can find it HERE.

A Closer Look at the HLXG Bulbs

After some more googling, I finally decided to go with the HLXG bulbs. The bulbs (sold as a pair) arrived in a well-packed and designed box. They are rated IP65. HLXG claims an output of 4,000 lm per bulb and the color is 6000k (white).

The body and heatsink are made of aluminum, while the removable base is made of plastic. A copious amount of heat paste has been applied between both aluminum parts to help evacuating the heat from the LED chips. Overall, I am quite impressed by the fit and finish of the bulb.

An H4 bulb has 2 filaments, one for low beam and one for high beam. In order to get a clean beam pattern in a halogen housing, the positioning and size of the LED chips need to mimic the filaments of the halogen bulb. And, as you can see on the picture below, that is exactly what HLXG has done. The LED chips are mounted on both sides of a very thin PCB.

Please don’t forget to take into account the height of the bulb, when choosing an LED bulb. The reflector inside the headlight housing has a cap that goes over the bulb. And, as far as I know, the only way to remove it is to split the housing… (delicate and time-consuming affair)

A is low beam ; B is high beam

Fog Lights

I purchased my Versys-X with the optional crash bars and LED fog lights. I happen to have a few spare fogs laying around, and decided to have a closer look. The lens is made of polycarbonate and the body is made of aluminum (acting as a heatsink).

Each fog light has two tiny LEDs, mounted on each side of the PCB. Both chips are rated 8W combined (at 12V). For such low power consumption, their light output is quite impressive. And they are made by PIAA, so you can bet your sweet life that they will outlast the bike (also explains why they cost an arm and a leg).

These lights have a bar-shaped beam with a wide field of view. There’s a yellowish hue in the middle of the beam, so I assume that one LED is 6000K, while the other is 3000K.

Power Consumption

I am no wizard when it comes to electrics, so this is going to be (too?) simple. From what I have read, the stator on the Versys-x generates 21A at 5,000 rpm. At 14V, this equates to 294W. I estimate the total load on the system around 237W:

Fog Lights2161.14
City Lights2100.72
Turn Signals 4402.86
License plate light150.36
EFI 1352.50
Radiator Fan1141.00

In stock form, there’s about 60W available for farkles. In practice it’ll be less, because you don’t want to load the system 100%. Personally, I will put my limit at 90% load. This would give me: 294 x 0.90 = 265 – 237 = 28W only to play with. I also have a power saving of 42W, thanks to the LED headlight bulb. This gives me a total of 70W available for farkles.

It is important to note that the system generates 21A at 5,000 rpms. If you’re doing a lot of riding below 5,000 rpms (or a lot of idling) with a high electrical load, there’s a chance you will deplete the battery.


I am quite pleased with the extra light output of the H4 LED bulb. It’s a good way to spend 20 USD and the power savings are an added bonus. As for the longevity, time will tell. So far, so good, but the weather has been quite cool (20-25°c) . So, I am eager to see how it will hold up during the summer months, when the temperatures hit high 30s. Worst come to worst, I still got the second bulb as a spare… Fingers crossed!

At the moment, I have 3 spare PIAA fog lights laying around. I have ordered the plastic housings from Kawasaki for 2 of them (parts no. 55020-1826 & 55020-1825). I’ll do some thinkering to see how and where to mount the additional fogs…

Update 01/2023:

  • The first bulb lasted around 18 months before it started flickering.
  • The second bulb is still running strong for nearly 24 months. However, I will be replacing it with a Philips Ultinon Essential H4 bulb.