
Install the Di2 battery in the fork steerer
Where do you install your Di2 internal battery if the seatpost isn't an option? On a full-sus mountain bike, or if you run a dropper post? One of the options you have is to install it in the fork steerer.

The Shimano SM-BTR2 is an older generation model internal battery that weighs about 50g, has a rated capacity of 500 mAh and a rated voltage of 7.4 V.
Its normal operating temperature range is between -10C and 50C. You charge the battery by connecting your charger to the Junction (A) box.
If storing the battery away for a long period, remove it when the battery level is 50% or higher (the indicator is illuminated green) in order to prolong its useful life. It is recommended that you charge the battery about once every half a year.
Store the battery or bicycles with the battery installed in cool indoor places (approx. 10 to 20 °C) where they do not become exposed to direct sunlight or rain. If the storage temperature is low or high, the performance of the battery is reduced, and its available time will be shorter. When you use the battery after a long storage period, be sure to fully charge it before use.
Note that this older battery is not synchro-shift compatible. You will need to use the newer BT-DN110 for that.
This battery will not work with the EW-WU111 / EW-WU101 Wireless Units or the SC-MT800 / SC-M9051 displays. It will work with the older SM-EWW01 wireless unit (ANT only) and SC-M9050 display.
If you are considering getting a display or wireless unit however, really consider upgrading to the BT-DN110 battery.

Where do you install your Di2 internal battery if the seatpost isn't an option? On a full-sus mountain bike, or if you run a dropper post? One of the options you have is to install it in the fork steerer.

I installed SW-7972 Dura-Ace satellite shifters on my 6870 commuter bike by doing some cutting and soldering, as well as some creative wiring.

On this page I'll show you how to install your Di2 seatpost battery BT-DN300/BT-DN110 or SM-BTR2 in your bike's seatpost.


