Volt Meter????
 

Although I have had my 2018 S5 Cab since August, I just noticed that there is no way to determine the battery voltage from the gauges or MMI. I know the vehicle has various ways it can determine if the battery voltage is getting low and shed power loads, etc. But it still seems that there should be some way of determining what the battery voltage is. Have I missed something?

The reason it came to mind is that the auto stop/start never activates in either D or S (and that makes me happy). I know that low voltage would be one of the reasons that stop/start wouldn't activate so I went looking for a voltage readout and couldn't find it. Looks like I need to get my voltage meter out and check just to make sure everything is OK.

It won't come on if you are running the air conditioner - are you?

Yes, but it was only 37 F degrees today. The wife's Sportsback stop/start operates with the ac/ heater operating.

Mine start/stop even with AC running,

Where can you find battery voltage?
 

Shoet of taking a voltmeter to the battery, I doubt it.

I have not tried it and will sometime this week, but it looks like VCDS might allow you to turn it on.
The list here is for B8 and not the B9 level cars, but many are the same settings.
B8/B8.5 VCDS & Hidden Menu: The Complete List

Enable Battery meter
[56 - Radio] -> Adaption -> Channel 39, add 16 to your value

Has anyone successfully gotten this to work on the B9 platforms???

Doesn’t really answer the question but as part of my Remote Start, the iOS App does provide a readout of the battery voltage:


https://cimg4.ibsrv.net/gimg/www.aud...13bd4e02a.jpeg



— John

I have the same app.
However, unless it's wired directly to the battery, you may (and I have seen) and 1-2v differential.
I've been seeing large voltage drops, and significant upswings - that occur within 5-10 seconds.
In other words, I could go from 14.7 to 12.5 in like 5 seconds.
This has just started, so I'm looking for an official voltage the car sees.
When I see these drops, I have plugged my OBD11 into the port and it confirms the drop, however. without know where the port is reading voltage (I.e., a fuse locations, off the alternator, etc.).
So, I was hoping to activate something similar to what was available in the B8.5 - it was on the MMI display, which you could turn on, but it wasn't on full time.
I've measured my voltage at the battery, and I seem to get 13v's continuous, but my concern is that it might not actually be what the control modules in the car are getting (I.e., my remote start reporting 12.2 volts, or my radar detector reporting same, blah blah blah).