Garmin · Cycling & fitness
Garmin Speed Sensor 2 battery
1 × 3V lithium coin cell
How to replace it
| Compartment | Sensor cover |
|---|---|
| How to open | Remove sleeve; rotate circular cover on front of sensor counter-clockwise |
| Orientation | Observe polarity marked in cover |
| Seal / O-ring | Do not damage or lose the O-ring gasket |
| Low battery indicator | LED flashes red after two revolutions when battery is low |
| Notes | Wait 30 seconds. Cover must be flush; LED flashes red/green then green when ready. |
| Access | Tool-free |
| Gasket / O-ring present | Yes |
Important
- Confirm in Speed Sensor 2 Instructions PDF on Garmin Support manuals tab
Sources
Helpful for this device
Optional tools for opening, testing or charging — separate from the battery answer.
- Coin cell / button cell battery tester
Quick check of CR / LR / SR button and coin cells before fitting
- Fluke 101 Digital Multimeter
Accurate open-circuit voltage and basic electrical checks
- Digital multimeter
Measure open-circuit voltage and general electronics checks
New battery but still not working?
A fresh 1 × CR2032 should restore Garmin Speed Sensor 2 if the battery was the problem. Work through the checks below before replacing the device.
- Check orientation
Confirm the cell is seated correctly: Observe polarity marked in cover
- Check the battery type
This device needs 1 × CR2032 (lithium). Rechargeable cells are not supported for this device. Same size does not always mean the same battery.
- Check known model-specific issues
Do not damage or lose the O-ring gasket Confirm in Speed Sensor 2 Instructions PDF on Garmin Support manuals tab
- Confirm the battery itself
For most coin cells, fitting a known-good fresh cell of the correct code is simpler than capacity testing.
- Still not responding?
If a correct, fresh battery installed properly does not restore the device, the fault may be elsewhere — the device may need service or replacement.