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Bontrager Ion 200 RT teardown, what inside?

Published: 26 September 2020
Last updated: 01 June 2024

The Bontrager Ion 200 RT /Flare RT light set is one of the best daytime running light for bicycles. It is not only very lightweight but also highly visible at long distance. The light set is of a particularly high quality. For my bicycle on solar energy, the Maxun One, I made daytime running lights myself and that is why I was curious how the Bontrager works. I cut the Bontrager Ion 200 apart to find out at what's inside.

Flashing light on solar bikeFlashing light on solar bike

Inside Bontrager ION 200 RTInside Bontrager ION 200 RTTeardown Bontrager ION 200 RTTeardown Bontrager ION 200 RT

Why daytime running lights?

Cars are an increasing danger to cyclists. This is because the motorist is distracted by operating the abundant of electronics in the car, such as navigation, smartphone, etc. A car sometimes looks like an airplane cockpit, with the difference that in an airplane there is a co-pilot to operate everything.

Bontrager Ion 200 RT holder 3D CAD model

I designed a holder in Freecad, you can customize it to your liking. See here at GitHub.

Bontrager Ion 200 RT holder 3D CAD modelBontrager Ion 200 RT holder 3D CAD model

How to open the Bontrager Ion 200 RT

The Ion 200 RT has been sealed by the factory. You have to cut it open with a knife but that takes a lot of effort. Re-glue it with PU glue.

OLYMPUS DIGITAL CAMERA         How to open the Bontrager Ion 200 RT

Lens reflector collimator

For bicycle lighting, you cannot properly use a bare LED without a lens because:

  1. The light surface of a LED is too small
  2. The beam angle is too large, usually 125 degrees, see Fig4.

That is why a lens, reflector and a collimator is used. The lens and reflector focus the light on a surface of 17 mm. The collimator consists of a bead surface of the lens and creates a parallel light beam, see Fig5.

Fig4 LED spatial distributionFig4 LED spatial distribution

Fig5 LED lens reflector collimatorFig5 LED lens reflector collimator

LED lens bead surfaceLED lens bead surface
LED lens reflector collimator parabolic shapeLED lens reflector collimator parabolic shapeLED lens reflector collimator inside viewLED lens reflector collimator inside view
Bontrager ION 200 RT LumensBontrager ION 200 RT Lumens

Read more about the reflector collimator here: LED Optics Explained.

 Circuit description

Teardown Bontrager ION 200 RT PCBTeardown Bontrager ION 200 RT PCB

Teardown Bontrager ION 200 RT circuitTeardown Bontrager ION 200 RT circuit


The Bontrager can be wireless controlled by a Garmin navigation device by ANT+. This is conceptually similar to 2.4 GHz Bluetooth low energy, but it is specialized for sensors.

Serial Wire Debug

Apparently, the device can be controlled by Serial Wire Debug via the USB connector. Note that the Bontrager connections of the USB are completely different from the standard.

Synchronous step-down converter

The converter operates at a frequency of 1.4 MHz, see Fig3. However, the LED current is not constant as expected, but it has a sawtooth shape with a much lower frequency, namely 1.6kHz, see Fig1. I wonder why this is made so.

LED current and luminous flux

The LED current can be calculated as follow:
UR1 = 50mV average, see Fig1.
I led = 50mV / 0,3Ohm = 170mA
With a Cree Xlamp XTEAWT-00-0000-000000HE4, the luminous flux may be about 170/350 * 150lm = 70lm.

Flash mode

In flash mode there are 3 pulses of 50ms and 2 pulses of 100ms, the period is 1,3s. See Fig2.
The total on time = 100+100+3x50 = 350ms

Battery life during sleep mode

The microcontroller and the two crystals are running during power off.
The sleep current is between 90 and 150uA, the average is about 120uA.
The battery life during power off = 420mAh / 120uA = 3500h = about 20 weeks

Battery life at flash mode

The average LED current = 0,35/1,3 * 167mA = 45mA
The theoretical battery life = 420mAh / 45mA = 9 hours
In practice it is approximately 5 hours.

Battery replacement

If the battery is worn out, you can replace it with a new one:
3,7V, 420mAH

Bontrager ION 200 RT battery replacementBontrager ION 200 RT battery replacement

Oscilloscope signals

Fig1 R1 shunt 200usFig1 R1 shunt 200usFig2 R1 LED current U2 5 feedbackFig2 R1 LED current U2 5 feedbackFig3 U2 3 switch 200nsFig3 U2 3 switch 200nsC7C7R6 from CPUR6 from CPUU2 1 enableU2 1 enableU2 3 switch 500msU2 3 switch 500msX2X2X2X2

Bontrager Ion 200 re-engineering

Bontrager ION re-engineeringBontrager ION re-engineering
Components inside the Bontrager Ion 200

White LED

Bontrager ION 200 RT LEDBontrager ION 200 RT LED

Probably Cree Xlamp XTEAWT-00-0000-000000HE4
Angle 125°
150lm at 350mA
Price $0,50


SMD code S2RV (I cannot find this code)
Charge management controller
Probably: MCP73831


Synchronous step-down converter
SMD code ZY881 (I cannot find this code)
Probably: TLV6256 or RT8096A or RT8008 or XM5062


Wireless microcontroller


SMD code 09GIS (I cannot find this code)
2,5V Voltage regulator


Bluetooth ceramic chip antenna


SMD code 6BAY (I cannot find this code)
Dual diode


SMD code 88198 (I cannot find this code)





SMD code 32.0Y (I cannot find this code)

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