FAQ: Di2 Wireless Shifter Battery Replacement: 2026 Guide & Critical 11% Warning
12-speed wireless di2 shift levers (ST-R9270/ST-R8170/ST-R7170/ST-RX825) run on CR1632 batteries.
They last for about 2-4 years and are generally not on top of mind. When they reach the 10% mark though, replace them within a month or you may find yourself without shifters for your next group ride.
The 5-Minute Fix:
- Check your level (Press both buttons).
- Look for the LED on the front of the shifter
- CRITICAL: If you see Red, replace the battery as soon as possible.
Step-by-Step Replacement:
I have a fully illustrated Di2 Battery Replacement Guide that shows exactly how to open the coin cell compartment without stripping the tiny screws and how to purchase the correct batteries.