Replacing the Internal Cells in Shimano Di2 Battery Packs

The battery packs that came with various Shimano Di2 electronic shifting groupsets deteriorate over time and will hold less and less charge each time they are recharged. Whole new replacement battery packs can be very expensive but fortunately the internal cells within these packs can be replaced. Below we outline the Di2 packs and the replacement cells that can be fitted to them.

replacement-internal-cells-shimano-di2-battery

Original Shimano Battery Packs

The original battery packs from Shimano include the following battery part numbers. These can be opened up and the two internal Li-ion cells can be replaced:

  • SM-BTR2
  • BT-DN110
  • BT-DN110-A
  • BT-DN300

The original battery packs were supplied with some of the following electronic shifting groupsets, and others:

  • Dura-Ace 9000 series
  • Ultegra 6800 series
  • Ultegra R8050

Replacement Cells for your Di2 Battery

The two internal cells are both 43mm long, 14mm diameter 3.7V Li-ion cells. The originals are 570mAh capacity but you can upgrade to higher 700mAh capacity for longer running time between recharges. The cells can be replaced with two new cells that have metal solder tags pre-welded to the ends. It is important to only use cells with solder tags pre-fitted as soldering directly to Li-ion cells can be very dangerous due to the heat. Be careful not to short circuit the new cells either.

replacement-internal-cell-for-shimano-di2-battery

New cells for your Shimano Di2 battery are available from the following sellers on eBay:

Please note that as an eBay Partner we may receive a small commission if you make a purchase. This does not change the price you pay.

Let us know in the comments section below if you have any questions, comment or tips!

10 thoughts on “Replacing the Internal Cells in Shimano Di2 Battery Packs

  1. Hello,

    Do you have a tutorial to recommend to change this battery by myself ?

    Best regards,

  2. Hi
    I can install 2 cell battery with 700mah too?

    1. Yes, two-cell Li-ion packs are available with the correct internal solder connections and 700mAh capacity will upgrade your battery nicely.

  3. Do these cells contain a protection circuit?

    1. No, neither the originals nor the replacements have protection circuitry attached to the cells themselves. The battery management circuitry is all on the PCB inside the battery housing.

  4. How easy is it to refit the cells into the Di2 case. Does it open up without force? Does it require soldering?

    1. The outer Di2 battery casing is held together by clips apparently. Once the insides have been slid out there are 3 solder connections on the old cells to desolder. Then the new cells are soldered in place.

  5. Hi,
    in the past I experienced that some battery management circuits have under-voltage-protection and if a certain threshold is undershoot, the circuit does not work anymore. Even if new cells are installed and charged. Only way to circumvent this was to solder batteries in parallel with the old ones after that I could remove the old ones.
    Is that also necessary or can I first remove the old batteries and then install the new?

    1. According to people who have carried out the repair the protection circuitry in the Di2 packs does not care about cells being totally disconnected. It works fine after new cells are soldered in place after full disconnection.

  6. Excellent stuff!

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