It would be nice to be able to pair di2 to Zwift:

 - Gear display

 - Battery level (I’ve run the battery out twice while Zwifting, doh!)


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Hey, this sounds like a fantastic idea.  

Consider this my vote =)

I presume you realise for this to work you would need the optional Di2 ant+ transmitter thingy?

I would imagine for those Di2 users who have this (I have one) they already use it to connect with a Garmin Edge to show gearing, battery etc? 

And how can you have run your Di2 battery flat just Zwifting? Mine drops to about 50% after several months of riding!

+2 on the battery life comment. I get at least 6 months of daily rides (each one typically an hour long) from a fully-charged Di2 battery.

If OP is truly exhausting his battery ‘while Zwifting’ I’d say it’s time to check his Di2 system – something is wrong.

@J. Hansen Thanks.  It would also be good to track gear info as part of the fit file Zwift generates.

@Stuart and @DB Yes, I have a SM-EWW01 or whatever it’s called  di2 transmitter on both of my di2 bikes.  I also have the e-tube software and programmer and the di2 all checks out fine.  I’ve done many miles and never run a battery down on the road precisely because the Edge will show me if the battery is low and I am my likely to check the status lights on the control unit than when I ride inside.  On the trainer with Zwift, I don’t see any reason to run my Edge at all.  I’ve tried it, but it’s not something I want to bother with.  I’ve been on Zwift for 15 months now, so maybe my experience is more extensive than yours.  I probably should do a more comprehensive check on the bike before I ride on the trainer just as I would outside, but there are actual many things I don’t do before every Zwift ride, like checking my front wheel quick release, tire pressure, di2 battery, etc.

I take it you guys who have di2 would rather NOT have the gears or battery level displayed?  Wow.  I’m sure it would be easy to just not pair the di2 ant unit if you don’t want it!

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I don’t have the Di2 ANT thing:

  1.  See no need to have either a batterylife indicator OR a display to tell me what gear I’m in!

  2. I ride about 3000 miles a year, both outdoors and on a trainer. I’ve been using Di2 since July of 2011. I’ve never had to charge the Di2 battery more than more than 2-3 times each year.

in any case I’d like to understand the theory that says using Di2 with Zwift uses more battery than riding outside! Don’t get that at all!



@DB If you don’t have the di2 ant component, then the feature is not something you could use anyway.

Personally, I think the gear display feature is even more useful to me on Zwift than it is on the road, because on Zwft with my KICKR, speed is derived from power output, and it is not a consistent function of gear ratio and Cadence as it is on the road.

As far as a theory that says Zwift uses more di2 battery than riding on the road, I have no clue what your referring to.

Certainly, the ant unit draws some current from the di2 system if you have it, but I don’t imagine it is significant.

In any case @DB, I understand you are adamant against this idea, and you are clearly far to awesome to ever need a display like that on the Garmin units, which show gear position and battery level.  Nevertheless, thanks for your valuable feedback on my feature request.

Although I’m sure it’s technically possible to read the Di2 ant+ data, I’m pretty sure for the very few that actually ride with Di2, and the fewer of those that have the ant+ transmitter, using the Garmin Edge is the only way it’s gonna happen, given what must already be a very large development roadmap for the software!

As it happens, I have Di2 on my road bikes but indoors for Zwift I ride a Wattbike; even so, just in case Zwift crashes on me or I have some network issue, I always have my Garmin on hand recording the data as a failsafe!

My comment was solely about your battery life claim. I have no comment on your feature request - I’d wouldn’t use it (even if I could) but I have no particular objection to having Zwift add it!

My post in reply to your 2nd/3rd posts was simply to establish that I have a fair bit of Di2 experience behind what I say - you implied that I, perhaps, do not.






@stuart  I think that’s a good idea recording the ride on the head unit for that reason.  I was doing that myself a year ago, but I found the speed and distance recorded by Garmin do not match Zwift because while the garmin records the speed output of the KICKR, Zwift ignores it, or at least seems to.  At this point, I’d just as soon put in a manual entry for the miles I lost.

I’ve only had Zwift crash on me once, and it was well into a century.  Fortunately, most of the data was recoverable with some utility a friend was using to merge two rides together when I did the final 10 miles or so.

@db Thanks for that, I may not have been clear on my first post.  The battery ran out twice on me during Zwift rides, but this was my fault because I didn’t know how low it was when I started the ride or during it.  I always know what my battery level is outside, because a. I have it on my garmin, b. I do a more thorough pre-ride inspection of the bike when I go outside, and c. the thong thingy that keeps sweat off my bike doesn’t block my view of the SM-EW90 junction box like it does when I’m inside.  Riding for me inside on Zwift involves much less prep, so I tend to pay less attention and eventually my lack of attention catches up with me.

When my Di2 battery got low during a recent Zwift ride, the front derailleur was load shed, and I got stuck on the small ring.  After that, I couldn’t keep up with my group.  So that was the impetus for my suggestion.

As already noted, I am not “adamantly opposed” to ANY feature Zwift wants to add (so long as using said feature is optional).

When Di2 first came out I seem to recall that Shimano claimed ‘at least 2000 miles’ battery life between charges. That claim matches my experience across three different Di2-equipped bikes.

I first commented because I was surprised by your claim that you ran out of battery TWICE while riding Zwift (over 15 months). It just seemed (seems) odd to me (based on my own experience). But maybe you did 3000+ Zwift miles over that period?..

I think battery life is a function of the number of shifts and not the number of miles, although 2000 might very well make sense for a typical user.

if one person shifts 500 times in a ride and another shifts 1500 times, they are likely to have very different results.

Also, the battery drains on its own, not very fast, but if you put your bike away for the winter expect the battery level drop significantly, just like most devices with lithium ion batteries.  batteries may also go down faster if the limit screws on your derailleur a are causing more load on the motors.

id guess I’ve had to charge by batteries once every 1000 miles on average, but I shift a lot.  Not sure how much compared to others, but I’m guessing more than average, especially in group rides.

@Michael Just to contrast, when I record a ride on my Garmin it also connects to my Wattbike computer via ant+ and receives all the usual data including a “speed” (lol). I presume this to be calculated via some metrics that take into account my weight and power given an average bike on a flat calm road! When I compare my Garmin ride to my Zwift ride they are actually pretty close - the longer the ride the closer of course, but an hour on Zwift will generally see my Garmin show the same distance/avg speed to within half a mile or less.

Also regarding Di2, I wonder if lots of frequent shifts of the front mech might account for the increased battery use (it uses more power than the rear)), perhaps you have a different riding style than for on the road.

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Does Di2 have a desktop companion app today? You might be able to turn that into an overlay and sit it on top of Zwift’s app screen, in a semi-transparent window. 

Or if it’s available on your mobile device, project that on your PC screen to get the data you need. 

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While I realize it would probably not be a high priority for development resources, the ANT+ data from the Di2 transmitter would just be another data point to put on the screen.  It’s not exactly rocket science to do. 

You could just stick the numbers in a corner of the same display panel where the other data (power/HR/cadence) already live.  Or, even better yet, give us the ability to toggle various elements of the UI. I don’t personally care much about the PR’s and Sprint/KoM stats, but I would like to see a scrolling graph of my HR, Cadence, and power (much like what we see in the workout screens now), even while just doing free rides.

And no, I don’t run my Garmin on my handlebar when I’m on the trainer.  In fact, I haven’t seen my Garmin since last summer :p~

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