Twelve-speed hydraulic Di2 shift levers can be set up to shift wirelessly. These shift levers are powered by coin cell batteries. There is one CR1632 in each Ultegra/Dura-Ace hydraulic lever, and two CR1632 batteries in the 105 Di2 shifters.
You’ll need to replace these batteries when they run out (after about two years for Dura-Ace/Ultegra, and four years for 105).
I’ll show you how to check the battery charge level of your Di2 shift levers, and how to replace the coin cell battery.
Check the battery charge level
There are two ways to check the shifter’s battery level - the first is using the E-Tube Cyclist mobile app, and the other method involves pressing buttons on the shifters itself.
My preferred method is to use the buttons on the shift lever itself, so I’ll show that first.
Check the shift lever battery on the lever itself
This method is by far the quickest and easiest, and it lets you check the battery level on a Di2 wireless shift lever in under a second.
How? Well, you simply press both shift buttons at the same time for about 0.5 seconds.
The LED on the shift lever will switch on, indicating the battery level:
- Green: 11% to 100% battery
- Red: 1% to 10% battery level
- No LED: 0%
If it’s green, you’re all good.
However, if your shifter LED turns red, you have about a month to go before it’ll go completely flat - buy a new CR1632 and replace that battery as soon as possible.
And yes, even though they're a bit harder to see, Ultegra and 105 levers do in fact have LEDs.
Check shift lever battery using E-Tube Cyclist
If you haven’t downloaded E-Tube Cyclist yet, make sure you do so. 12-speed Di2 systems come with BluetoothLE/ANT connectivity out of the box, so there is no reason not to have the app.
The app is available for both Android and iOS, and I’ve put links to the app on my Tools & Software page.
To connect to the bike, press-and-hold the button on the rear derailleur for 0.5 - 2 seconds. The LED will flash blue, indicating the bike is ready to connect over BluetoothLE.
Make sure Bluetooth is enabled on your phone, start E-Tube Cyclist, and connect to the bike.
After connecting successfully, open the maintenance tab. This is where you’ll see your shifters and their battery level, as well as the main battery - BT-DN300.
Chances are though, that your shift levers don’t immediately show their battery level. Instead, you’ll see a dash (-).
To check the battery status for your levers, tap that ‘refresh’ icon - see the red arrow above.
E-Tube Cyclist will ask you to press any of the buttons on your left lever, to ‘wake up’ the shift lever. Next, it’ll prompt you to press a button on the right lever.
That’s it! You will now see the battery charge level indicated by either a green or a red circle.
- Green: 11% to 100% battery6
- Red: 1% to 10%
If the circle is red, indicating a low battery level, replace yours within a month.
Replace your ST-R9270 / ST-R8170 shift lever battery
The hydraulic shifters have wireless functionality, and this works using a CR 1632 battery. Replacing this battery is an easy affair, and takes about two minutes.
There’s a guide showing you how to replace the battery below, but if video is more your thing, I’ve uploaded one to YouTube and embedded it here:
The battery is stored in the shifter hood, so pull back the lever cover to get to it:
Right at the top, you see the battery door (also: battery holder) - being held in place by that little screw. Take your screwdriver (flat, 0.8 x 4) and loosen the screw.
You can leave it in the battery holder if you like, but I prefer to take it all the way out and place it somewhere safe - that way you can’t lose it.
Open the battery holder, and you’ll see the battery right here:
It doesn’t come out that easily - it is secured by a little spring and just pulling it out won’t do.
Instead, you push down on the battery, and then slide it out. Sometimes the smooth top of the battery won’t give you enough friction to pull it out. Shimano advises against using pliers or other metal tools to force the battery out, as this could cause a short and possibly electronic malfunctions.
What you can do though, is take a bit of tape, and stick it to the top of the battery. You then push down and pull it out at the same time.
According to the dealer manual, you should now inspect the (grey) seal for damage and dirt. Unless you’re riding your bike in horrendous conditions though, I don’t think you have to worry about that.
To install the new battery, you insert it into the battery holder with the positive (+) side up, and then gently close the battery holder. That’s it.
Tighten the screw, and wiggle the hood cover back into place.
Note that the screw should be tight, but not too tight. Its job is just to keep the battery holder/door closed, and that’s all. You do not want to strip the threads on your expensive shift lever.
Once the battery has been installed you can immediately get back to riding. There is no need to re-pair the levers.
Replace your 105 / ST-R7170 batteries
The 105 shift levers have two batteries, and they'll last a very long time. You are unlikely to ever need to replace them. If yours ran out of juice though, be sure to follow the process described above - with one subtle difference.
These levers have a slightly different battery port, and that opens up instead of to the side. To get to the port, pull back the front of the lever hood.
Here's an image of a 105 lever:
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Questions, comments, leave them here
Did you successfully replace your battery? How long did yours last?
If there’s anything unclear or you need any help, feel free to leave a comment below, or send me a message!