Shimano 9070 Di2 external & internal batteries

Discuss light weight issues concerning road bikes & parts.
Posts: 271
Joined: Mon Feb 18, 2008 9:47 pm
Location: TX

by Hubert

The "bulgy" sleeve is indeed a Trek part and not a Shimano part.

From the factory, the SMBTR2 battery does not come with any type of adapter.

I used an o-ring around the battery, shoved it into the seatpost of my TCR (aero seatpost) and then made up the difference with packing foam - work's just fine.
Turn down the suck knob.

by Weenie

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Joined: Sat Mar 10, 2012 1:00 pm

by notaero

Can this battery be charged through the "old" style junction box jc-4x if I disconnect a cable, or must this be through the new Ew-90-x models? Sorry if this is explained elsewhere I'm confused. Thanks.

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by mlchang

The charging port on the new junction box is some type of USB port separate from the other plugs. The charger does not plug into one of the cable ports. So you need one of the new junction boxes. Also need to update firmware.

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Joined: Sun Mar 27, 2011 8:16 pm

by Dammit

Battery, AKA round hole:


Charger, AKA square peg:


As far as I can see there is absolutely no way to connect the internal battery charger to the internal battery itself, you have to get the new junction box.

I've ordered the junction box from and will finally allow me to put everything together.

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Joined: Mon Dec 31, 2012 5:27 am

by freeloader

Hi All,

i wondering if the following setups would work -

1) DIY or third-party charger
a) Cable Junction SM-EW67-A-E
b) Internal Battery SM-BTR2
c) Charger with DIY connector to plug into EW-SD50 cable
2) SM-BCR2 Charger
a) Cable Junction SM-EW67-A-E
b) Internal Battery SM-BTR2
c) SM-BCR2 Charger, with DIY adapter to plug into EW-SD50 cable

With setup 1, the cost is reduced by not using 1 x SM-EW90-A junction, 2 x additional EW-SD50 and 1 x SM-BCR2 Charger (substitute with 8.4V, 0.4A charger).
With setup 2, the cost is reduced by not using 1 x SM-EW90-A junction, 2 x additional EW-SD50. The OEM charger is used for firmware updates.

Both setups are based on the assumption that the SM-EW90-A junction does not have any circuitry. It seemed to be the case as charging with SM-PCE1 can be done at any exposed connection - Besides cost saving, the advantage of this approach is no hacking to the OEM parts is required.

Posts: 52
Joined: Fri Sep 30, 2011 4:48 pm

by 415brian

I just received the SM-BTR2 internal battery. To install in a seatpost, Shimano includes a plastic shim, some washers and a snap ring. These bits are only useful if your seatpost includes a Di2-ready/friendly sleeve.

I have an 27.2mm FSA K-Force seatpost from a stock Cannondale EVO Hi-Mod Di2 that includes such a sleeve. I don't know if FSA or Cannondale installed the sleeve, but it seems semi-permanent. Battery installation pics...


Alternative #1: a little foam and zip ties:

Alternative #2: ask a Trek dealer to help procure this elegant rubber leaf spring:

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Posts: 81
Joined: Wed Jul 16, 2008 10:38 pm
Location: North Wales

by keith

My LBS have just taken delivery of most of my Di2 parts. Apparently Shimano have specified how to design a seat post to hold the internal battery and secure it with the parts they supply. To date very few manufacturers have started to modify their seatposts to do this.
Riding my road bike in North Wales

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Joined: Fri Sep 30, 2011 4:48 pm

by 415brian

here's a scale shot with the battery installed...


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Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

So, no more cutting down seatposts to save weight?

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Joined: Sat Sep 19, 2009 12:23 pm

by v70cat

Someone else ask this but I don't see an answer

Can you use the internal battery on a 2013 Cervelo S5?

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Joined: Mon May 04, 2015 8:22 pm

by jorisee01

Where do you want to put it? It only fits In the seat down tube.

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