Ballast Testing: Pro Tuning Lab “CANBUS HID” 35W kit

Updated 7/5/17 – See temp data below!

This post is part of the Ballast Testing series, where kits are evaluated against the SKBOWE TestBench.

H11 35W DC CANBUS HID Xenon Headlights Conversion Kit


protuninglab 35w kit in box

The Protuninglab 35w kit in box

This kit is being peddled on C30crew as direct-fit compatible, allegedly no SKBOWE or relay harness required. Well, we shall see about that… Picked one up for testing, note that the ballast case is not as pictured online.

The kit does indeed run without a SKBOWE, even at DRL duty cycles. There’s a catch though!

protuninglab kit scope trace with no skbowe
Voltage and current for the ProTuningLab 35W kit when run without an SKBOWE

That current (red line) is off the chart – the peak is over 15A in every cycle! The thin purple line is where the red line should be. This current distribution is characteristic of a “warm start” strategy where the arc is extinguished and re-initiated every cycle, but at low voltage (without using the ignitor) rather than ignition voltage (30kV).

This is not good for the CEM  or the ballast, indeed the integrated “error canceler” gets VERY hot after a short time. Notice the noise on the input voltage – this will only get worse as the internal components age – and is what can cause WMM failure without an additional ground point.

Update 7/5/17 – Upgraded test bench data

On the upgraded test bench, after about an hour the relative output dropped 10%. The whole time this 35W kit is pulling 55W (i.e. wasting 20W somewhere). But the real question is how hot is really hot?

ProTuningLab 35W CANBUS after 1hr of operation
ProTuningLab 35W CANBUS after 1hr of operation showing 145-150°F, i.e. a 80° rise in temperature from 70° ambient.

The “error canceler” on this thing hit 150°F, which is a +80° rise over ambient. In the car’s engine bay that starts around 140°F, this thing would be running near 220°F or 105°c – literally the top of the temp range for the cap(s) inside. I suspect that there is a resistor in there causing some of that heating, but it runs cooler at higher duty cycles so there is something else going on.

Stay tuned, when production is complete this bad boy will get dissected!