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Introduction

Polar is producing fine gear for athletes giving them the information about their training. Usually only delivered Polar software lacks of updates but with the cadence Sensor same as the speed sensor, Polar managed to make a simple battery change a mess. I’ll show you how to successfully change the battery of the POLAR CADENCE SENSOR BLUETOOTH® SMART.

  1. Removed Cadence Senosor from frame
    • Removed Cadence Senosor from frame

  2. Either use hacksaw or Dremel to cut open downside of the sensor. Use the carve of the body for guidance. Either use hacksaw or Dremel to cut open downside of the sensor. Use the carve of the body for guidance. Either use hacksaw or Dremel to cut open downside of the sensor. Use the carve of the body for guidance.
    • Either use hacksaw or Dremel to cut open downside of the sensor. Use the carve of the body for guidance.

  3. After cutting the downside, sensor can easily be opened. Remove circuit board with care not to break the pin. Remove copper clamp with tweezers. After cutting the downside, sensor can easily be opened. Remove circuit board with care not to break the pin. Remove copper clamp with tweezers. After cutting the downside, sensor can easily be opened. Remove circuit board with care not to break the pin. Remove copper clamp with tweezers.
    • After cutting the downside, sensor can easily be opened. Remove circuit board with care not to break the pin. Remove copper clamp with tweezers.

  4. Replacing the battery
    • Replacing the battery

    • Move magnet close to diode. Flashing indicates successful replacement

  5. Glue it up (maybe nicer than I did) Glue it up (maybe nicer than I did)
    • Glue it up (maybe nicer than I did)

    • Second functional test with glued chasis

  6. Bonus IC Identification:
    • Bonus IC Identification:

    • Texas Instruments MSP430F5502 16-Bit Microcontroller w/ 24 KB Flash

    • Nordic Semiconductor nRF8001 Bluetooth Low-Energy Transceiver

Conclusion

To reassemble your device, follow these instructions in reverse order.

Milena

Member since: 04/06/2021

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One Comment

I used a razor blade in a box cutter knife (very carefully!) to gradually cut through the glue in the seam at the bottom of the device. It took many careful, small cuts to finally cut through so I could carefully pry the device open. After replacing the battery and testing it, I glued it back together with a crafting hot glue gun. This type of hot glue is waterproof, but you need to make sure there is no gap around the entire device seam. I was able to make a reasonable seal all around the device, and then I used a vice clamp to hold it together for drying. Next is outdoor testing.

Albert - Reply

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