Is there any modification making possible to check battery state of charge without VCDS for a Passat B8?

[--O-o-O--]

Dear Gentlemen,

I would like to ask you, if it is possible to check the battery conditions like actual voltage, actual charge, etc. without VCDS?
My car is a VW Passat B8 from 2019, off course I can read out them all with with VCDS through the CAN Gateway and the Advanced Measuring Values (DE01839 -- Battery charge condition), but I
would like to have it from menu on the instruments if possible on my car.
Reason is, that we use the Webasto auxiliary heater if it is cold outside because of our children, but drive only 10-15 minutes after the pre-heating., so actually I have to load the battery every day...

What I found till now does not work on my Passat, these are:
"Battery State of Charge percentage 17- Instruments 10- Adaptations Scroll down until you see Battery Charge, simply change it in the new value drop down to "active" and it's done." - I don't have Battery Charge under Instruments/Adaptions...
"Hidden menu in MMI high: STG 07 - Control Head - STG Adaptation -> Channel 8 - change 0 to 1" I don't have Control Head...

Other changes like changing the voltage for disabling the start/stop system, and the notification sound during closing and opening the doors are working perfectly.

Thank you in advance!

Regards

Toni

 

[TBAx]

I don’t think you can. They had in early MQB cars but removed the functionality, due to being misleading.

 

[DV52]

@--O-o-O-- : Hi.

Yes, don't both looking for the SOC channels on a MY19 MQB vehicle, cos it ain't there anymore - as @TBAx says. The old SOC readings that were displayed needed to be interpreted within the context of the headroom that the battery capacity required to accommodate regeneration (for cars with Start Stop). So the reading was never 100% (the reading generally sat between 70%-80%) - which doubtless resulted in lots of warranty questions from drivers - which (as @TBAx suggests) probably resulted in the removal of the facility entirely from the control module.

If you want to add an indicator of battery stuff (without the need for wiring mods), perhaps one of those USB based condition monitors might suit - maybe? Lots of these on the web from which to choose!

 

[--O-o-O--]

Thank you Gentlemen! Maybe it depends on the low outside temperatur - it is frozen now - that the car did not want to start today after 60 minutes of preheating. Starter motor turned, but was not able to start the engine. I have checked the logs, it was 11,5Volt only... Battery is together with the car 18 month old, and had together side by side approx. 61tkm. After deleting all dtc and loading the battery it started again. I think the battery frequently goes empty, because the engery management system is not able to load the car in the relative short distance and driving period after the preheating. Statistics is really 60minutes preheating followed by approx 15 minutes of driving. Is there any possibility to force the engery management system to load the battery? Many thanks in advance!

 

[DV52]

@--O-o-O-- Not sure if you are aware of a bunch of adaptation channels in the hex19 module on MQB platform vehicles related to displaying various warnings on the EM system. Here's a list from my Audi A3:

ENG137060-ENG113874-EM_energy_management_warning_displays-Batteriemeldungen
ENG137060-ENG98711-EM_energy_management_warning_displays-Charge level
ENG137060-ENG113873-EM_energy_management_warning_displays-Generatormeldungen
ENG137060-ENG118686-EM_energy_management_warning_displays-MMI Vorwarnungen

On most the admaps that I've seen, these channels are factory set to "Mode not active". I've tried altering the settings for these channels on my test bench and various warnings come-up - but the artificial environment of the test-bed and the fact that I don't have a fully operational EM facility makes it difficult to understand what's happening.

I don't think that any of these channels will solve your situation (I suspect that you need a trickle charger connected to the battery whilst the car is not in use), but If you are interested, you could experiment on the Passat

Don

 

[PetrolDave]

I think the battery frequently goes empty, because the engery management system is not able to load the car in the relative short distance and driving period after the preheating. Statistics is really 60minutes preheating followed by approx 15 minutes of driving. Is there any possibility to force the engery management system to load the battery?

Sounds like you take more out of the battery than the alternator can replace in the 15 minutes of driving, which isn't due to a problem/failure of the BMS but just because the Ah (Amp hours) you are taking out of the battery is greater than the alternator (even at full output) can replace in 15 minutes driving.

One suggestion to confirm this - get a battery voltage monitor that plugs into the 12V auxiliary socket (cigarette lighter it used to be called) when driving so you can check that the charging voltage is correct for the alternator at full output. I've been using one of these during Covid-19 lockdown and found it very informative.

 

[--O-o-O--]

At first thanks to all who have replied. I think I have identified the root cause...
Energy management system is programmed from factory to shut down the auxiliary heater at a voltage of 11,3Volt, but the most systems run into trouble already at 11,5Volts.
So Energy management system would shut down the heater if it is already too late.

At running engine (I don't know if this was the reason for success) I was finally able to reprogram in the aux. heat menu -> adaption the item "IDE06686-Insufficient voltage treshold" from 11,3V to 12V.

Regards