How to Check Shimano Di2 Battery Levels?

By : Mr Mamil
Updated :

This article discusses how to check the battery levels for all Shimano Di2 groupsets (10, 11, and 12-speed Shimano Ultegra and Dura Ace).

Shimano Di2 R9200 / R8100 (12-speed)

Shimano Dura Ace R9250 Rear Derailleur Diagram
Photo : Shimano

The latest 12-speed Shimano Di2 groupsets have a different method to check the battery levels than its predecessors.

Quick press (less than 0.5 seconds) the function button located in the rear derailleur. The LED color and flashes on the rear derailleur indicate the battery levels.

  • 51% – 100% – Solid green
  • 26% – 50% – Flashing green
  • 1% – 25% – Solid red
  • 0% – No lights

Shimano Di2 R9150 / R9000 / R8000 / R6870 (11-speed)

Shimano Di2 Battery Level Indicator Lights (SM-EW90)
Photo : Shimano

Press and hold any buttons (pick one only) on the shifters for at least 0.5 seconds. The LED color and flashes on Junction A indicate the battery levels. The Junction A can be located under your stem, at the end of the handlebars, or on the downtube depending on your setup.

  • 100% : Solid green for 2 seconds
  • 50% – 99% : Flashing green for 5 times
  • 25 to 49% : Solid red for 2seconds
  • 1% to 24% : Flashing red for 5 times
Shimano SM-EW-RS910 Junction A Diagram
Photo : Shimano

The LED will also indicate the shifting mode you’re in after the battery level indicators go off, depending on your firmware version.

Shimano Di2 R7970 / R6770 (10-speed)

Shimano SM-EW79A-E Junction A Diagram
Photo : Shimano

Press and hold any buttons (pick one only) on the shifters for at least 0.5 seconds. The LED color and flashes on Junction A indicate the battery levels. Junction A is usually located under the handlebars, next to the brake cables.

  • 100% : Solid green for 2 seconds
  • 50% – 99% : Flashing green for 5 times
  • 25 to 49% : Solid red for 2seconds
  • 1% to 24% : Flashing red for 5 times

What happens when the battery gets low mid-ride?

The front derailleur will stop working when the battery level is below 10%, and the chain will be stuck on the chainring you’re riding.

At this point, you want to be conservative with the number of rear shifts and get home as soon as you can before the battery runs flat.

Can I charge my battery before it gets low?

It’s a good habit to charge the Di2 battery regularly.

A full charge can last anywhere from 2,000 to 5,000km, depending on the number of shifts. Rather than counting the miles, make it a habit to charge the battery every 4 to 5 weeks (based on a 1,500km monthly mileage).