Check Di2 shifter battery level and replace it
12-speed wireless Di2 shifter batteries last about two years, and this page will teach you how to check the battery level and replace the battery itself.
Disc Brake Dual Control Lever (Wireless)
GRX ST-RX825
Twelve-speed GRX Shift levers feature one SD300 port, one satellite shifter port, and three shift buttons.
The third button isn't on top of the shifter but on the inside, where you would rest your thumbs.
Like the 105 Di2 shifters, these GRX units take two CR1632 batteries. They should last for about 3.5 - 4 years.
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Wired compatibility
If you've looked at the compatibility information for 12-speed Di2 then you might've noticed that ST-RX825 has no official wired compatibility.
Regardless of what the compatibility information says, you can in fact wire up these shifters no problem. They'll show up in E-Tube Project as you'd expect, and shift wired just fine.
Specifications
- Model code: ST-RX825
- Series: GRX (RX825)
- Weight: 207g (per lever)
- Speeds: 12
- SD300 ports: 1
- Satellite Shifter ports: 1
- Battery: CR1632 (2 per lever)
- Wired shifting: Yes (optional)
- Wireless shifting: Yes
- Servo wave: Yes
- Free stroke adjust: Yes
- Reach adjust: Yes
- Brake type: Disc
Related components
View all componentsRelated pages
Update the firmware on 12-speed Hydraulic Shift levers
Updating 12-speed Di2 R9270/R8170/R7170 shift levers is not as straightforward as you might think. You need either the SM-PCE02, or connect the levers to the rest of the system using an EW-SD300 wire.
Connect 12-speed Di2 shifters by wire
12-speed Di2 rim brake shifters can only be connected by wire - there is no wireless option for these shifters. Even if you're on wireless disc Di2, you may still be interested in connecting your shift levers by wire to increase battery life and eliminate wake up shifts.
12-speed Di2 New User Guide
Just bought a new 12-speed Di2 bike? This page explains what the buttons do, how to charge, and what synchronized shfit does.
Install 12-speed satellite shifters (EW-RS801)
Shimano 12-speed satellite shifters are tiny buttons or shifters that you can place in the drops, on the tops, or on your aero extensions. This page explains how to install the different satellite shifters and how to wrap the handlebar tape around them.
Pair 12-speed Wireless Di2 Shifters
I'll show you two different methods of pairing 12-speed Di2 wireless shift levers - using the mobile app and using wires.
Unpair 12-speed Wireless Di2 Shifters
Unpairing 12-speed Di2 wireless shift levers can be done using the mobile app or using the SM-PCE02 and E-Tube Project for Windows. This page describes both methods of unpairing wireless shifters.
Manuals & other documents
Firmware updates
Below is an overview of all known firmware updates for this component. The changelog texts are Shimano's, and quite often they're a bit cryptic - sorry!
4.0.1
■ ChangesSecurity performance for wireless communications between the shifter and rear derailleur has been improved.Click here to view FAQs for more information. https://bike.shimano.com/faq/DI20A#D-7030*The firmware for both the shifter and rear derailleur must be updated for proper operation of the Di2 system.* Wireless firmware update is not available for this product.Update the firmware over a wired connection or contact your place of purchase or a distributor. ■ OthersGeneral bug fixes.
4.0.0
Firmware released.
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