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Whether you run 11-speed Di2 or 12-speed Di2, chances are pretty good that you have a seatpost battery - either the [BT-DN110 10-/11-speed](/component/internal-

small_component-battery-holder.png

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I'm using a Deda battery holder in my [BetterShifting Cinelli](/build-log-cinelli-veltrix-disc-di2/#seatpostbatteryandbatteryholder), but any will do, really.

PRO make them, as well as Deda, Ritchey, Cannondale, Giant, and many others. 

Most will fit round seat posts, and come in different diameters. Make sure you get the one that matches your seatpost. If your seatpost isn't round, double-check with your bike's manufacturer.

If you've ever tried to remove a Di2 battery and battery holder from a seatpost you know that this can be tough if you're using a *seatpost battery holder*. They are meant to hold the battery in the seatpost securely, without it falling out when riding over rough terrain or even cobblestones. These generally work really well and I haven't ever heard of batteries dropping down the seatpost.

Sometimes they work *too* well. 

Sometimes your battery is stuck inside the seatpost and you just cannot take it out.

In that case, it can be tempting to just grab your pliers and try to get the battery out by (hopefully) grabbing the battery holder and pulling it out. Some people even use pliers on the battery itself.

![Di2 remove battery from seatpost pliers](https://assets.bettershifting.com/unstuck_battery_dont_do_this_c2adefa5bd.jpeg)

Please don't.

## Do not use pliers to remove a stuck Di2 battery
Thing is, while it may work *eventually*, you are very likely to damage or even ruin either the battery holder or the battery connector itself. You may be able to get away with using pliers on a 31.6mm seatpost, but it will just not work at all on more modern 27.2mm or Cannondale's 25.4mm seatposts. 

So what tools should you use instead?

## Use a J-bend spoke to extract your Di2 battery from the seatpost
Yep - all you need is a simple J-bend spoke. Any spoke will do -  as long as it is a J-bend spoke. Don't use an expensive or exotic spoke as you'll probably bend the spoke taking the battery out the seatpost. Don't have a spoke? Just buy one. You can buy spokes in any quantity and your local bike shop probably has plenty. A single spoke isn't expensive and can be a nice tool.

In order to remove the battery from the seatpost, this is what you do:

- Take your spoke in one hand and the seatpost in the other
- Now insert the J-bend side of the spoke into the seatpost, slip it between two halves of the battery holder for example
- Push the spoke in until just beyond the battery
- Turn the spoke so that the J-bend hooks onto the battery
- Now pull

![Di2 remove battery from seatpost use a spoke](https://assets.bettershifting.com/unstuck_battery_slide_spoke_62a4973d4c.jpeg)

Hook the spoke onto the battery just like this:

![Spoke close-up](https://assets.bettershifting.com/unstuck_battery_spoke_489014bdc8.jpeg)

Note that you may have to pull quite hard. The last time I did this myself I bent the spoke, making it easier to hold onto it *and* allowing me to pull the battery out straight.

Do not worry about pulling too hard and breaking the battery. The end of a Di2 battery can definitely take some abuse. If you are using an expensive carbon seatpost *do* take some care not to bury the J-bend into the inside of your seatpost.

![Di2 remove battery from seatpost tools end result](https://assets.bettershifting.com/unstuck_battery_end_result_9f8de9c08a.jpeg)


## Questions, comments
Have you ever had to remove a battery from a seatpost? Or any other part of the bike? How did that go? Still having problems?

If you have never installed a battery in a seatpost, [read how to do that here](/internal-seatpost-di2-battery-installation-guide/).

Leave [me a message](/contact/) or just post a comment below.




unstuck_battery_featured

Are you trying to take out a Di2 seatpost battery? Is it stuck? Before you take your pliers to it and ruin the battery or the seatpost itself, try using a J-bend spoke instead.

Remove a stuck Di2 battery from a seatpost

The Shimano [BT-DN300](/component/internal-battery-bt-dn300/) and [BT-DN110](/component/internal-battery-bt-dn110) internal batteries can be installed in a number of places: the fork, MTB handlebar, a really long stem.. anywhere that fits really. 

You will most often find it installed in the seat post and for a good reason: this way it is close to the derailleurs (12-speed Di2) and [junction B](/component/internal-junction-b-sm-jc41) (11-speed Di2).

This guide was originally written for the 11-speed [BT-DN110](/component/internal-battery-bt-dn110), but works just as well for the 12-speed [BT-DN300](/component/internal-battery-bt-dn300/). The dimensions of these batteries are the same, and the only place they differ is the connector block.

Because of the larger connector block, not every seat post battery holder will work with the [BT-DN300](/component/internal-battery-bt-dn300/) battery. Information on which does and which doesn't is on the [BT-DN300 component page](/component/internal-battery-bt-dn300/).

![BT-DN110, washers and seatpost holder](https://assets.bettershifting.com/install_guide_seatpost_bt_dn110_washers_72742d3af8.jpeg)

### Di2 battery washers adapters
Despite many manufacturers advertising “Di2 compatible” seat posts, you can install the battery just fine in a regular seat post – as long as it’s round. All you’ll need to install the battery in a non-Di2-compatible seat post is a seat post battery holder.

Feel like skipping ahead? Use these links:

- [Install the battery into a "Di2 compatible" seatpost](#di2seatpost)
- [Install the battery using a seat post battery holder](#batteryholder)

**Note**: *If your frame is equipped with an aero seatpost please consult your frame manufacturer for Di2 battery installation guidance as regular battery holders won’t do.*

## Install in a Di2 compatible seat post {#di2seatpost}
If you have a Di2 compatible seat post like the PRO Vibe (carbon), you won’t need any additional seat post battery holder.

Your seat post will have come with a Di2 battery collar (holder). It will probably already be installed, but if it isn’t, install it.

![Install BT-DN110 seatpost collar](https://assets.bettershifting.com/install_guide_seatpost_seatpost_di2_collar_8425d4d605.jpeg)
Now take the two black adapter plates that came with your battery and put them around the battery and slide the battery into the seat post collar until the adapters slide into place.

![Battery installation shims](https://assets.bettershifting.com/battery_installation_shim_a2fcdd16b5.png)

 Next you’ll have to install the washers. First install a flat washer, then the wave washer, and finally the second flat washer.

![Install BT-DN110 seatpost washers](https://assets.bettershifting.com/install_guide_seatpost_di2_snapring_and_washers_f76f090853.png)
To fix the battery in the seat post and finish its installation you’ll have to insert the snap ring. Take a set of snap ring pliers with a claw diameter of 2 mm or less to mount the snap ring and place it on top of the final washer.

![Install the washer snap ring](https://assets.bettershifting.com/install_guide_seatpost_di2_battery_washer_snap_ring_b232360612.jpeg)
Your battery installation is now complete – all that’s left to do is to connect the battery to the rest of the system using an electric wire.

## Install the battery with seatpost battery holder {#batteryholder}
You could try to install the battery without a battery holder if you really wanted to, but make sure you secure it well – you do not want it to slide out or start rattling whenever you ride across bumpy terrain.

As far as I'm concerned a Di2 seat post battery holder is the only real option. All the major brands make these, both in the 27.2 mm and 31.6 mm sizes.

The [Ritchey](https://amzn.to/2OfL2pk) and [Zipp](https://amzn.to/2BWysZi) ones below can be bought on Amazon or eBay – click the links to go to their product pages. Of course Shimano makes one too, the [PRO Di2 battery seatpost holder](https://amzn.to/3fjDHAG).
![Seatpost battery holders](https://assets.bettershifting.com/install_guide_seatpost_battery_holders_db0e37f990.jpeg)

So now that you have your seatpost battery holder of choice, it’s time to install the battery. The images we’ll use on this page show [PRO Di2 battery seatpost holder](https://amzn.to/3fjDHAG), but the process is similar for other brands’ holders.

![Install seatpost battery rubber holders](https://assets.bettershifting.com/install_guide_seatpost_pro_seatpost_battery_holder_411ffa65a6.png)
Take the rubber adapters and slide them around the battery as shown above. Make sure you can still access the e-tube port. Now would be a good time to remove the dummy plug from the port.

![Slide the Di2 battery into the seatpost](https://assets.bettershifting.com/install_guide_seatpost_pro_seatpost_battery_holder2_edad628038.png)
Then slide the battery and rubber adapters into the seat post. This will fix the battery in place.

That’s it, you’re all done! You can now connect the rest of the system and finish installing your [Di2 components](/components-and-accessories/).

## A note on removal - or uninstalling
Some Di2 seat post battery holders work *really* well. They work so well that they can make it next to impossible to remove the battery from the seat post. In these cases you can usually get the battery out by taking a **J-bend spoke** and inserting it into the seat post, hooking the bent part of the spoke behind the battery holder. You should now be able to pull it out.

I've written a page on doing exactly this. Interested? Read more on [removing a stuck Di2 seatpost battery](/remove-a-stuck-di2-battery-from-a-seatpost/).

install-guide-seatpost-di2_snapring_and_washers

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

Installation guide: Di2 Internal seatpost battery

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This page describes the process of building up a Cinelli Veltrix Disc with a full Di2 R8050 Ultegra groupset and the Shimano FC-R9100-P Power Meter.

Build log - Cinelli Veltrix Disc Di2

All of the Di2 hardware is completely cross-series compatible, meaning that you can mix Ultegra with DURA-ACE and even mtb components if you want to. The hardware below is used on both the Ultegra and DURA-ACE groupsets - and MTB and GRX as well.

Seatpost Battery Holder

Non-series components BT-HLDR

Affiliate Links

Specifications

Related components

Related pages

Remove a stuck Di2 battery from a seatpost

Installation guide: Di2 Internal seatpost battery

Build log - Cinelli Veltrix Disc Di2