T-Roc Battery Drain Causing Multiple Electrical Failures

Having some experience with VW electrical systems, I faced nearly identical issues with my 2021 T-Cross last winter. The symptoms match exactly what you described, weak starts, flickering lights, and multiple electrical system warnings. After dealing with what I thought was just a discharged battery, the workshop diagnosed a faulty battery sensor. This component monitors battery charge status and manages the charging system. When it fails, it can cause the exact symptoms you mentioned, even with a perfectly good battery. The repair cost was 315€ and took about 2 hours to complete. Since the fix, the electrical system has worked flawlessly with no more dead battery situations or error messages. Before jumping to conclusions though, could you share: Current battery age, Specific error codes from the OBD scan, Whether problems occur more during cold starts or also while driving, If any aftermarket electrical accessories were installed This information would help determine if your issue matches the battery sensor problem I experienced or points to something else in the electrical system. Remember that electrical issues can be tricky to diagnose since a low battery can cause similar symptoms to sensor failures or alternator problems.

Had a service just 2 weeks ago and with 111576km on the clock, I can confirm I am experiencing these exact issues. The battery is actually the original one from 2023, and the problems mainly occur during cold starts. No aftermarket accessories installed. OBD codes show P0562 and P0563, which relate to system voltage being too low and too high. This makes me think the alternator might be overcharging to compensate for a dying battery. Given the age of the battery and these symptoms, I am leaning towards a simple case of battery failure rather than a sensor issue. Will get the electrical system checked to be certain.

Based on your OBD codes and symptoms, this sounds different from my sensor issue. Those voltage codes typically indicate a failing battery or alternator regulation problem, not the battery sensor fault I experienced. Given that your original battery from 2023 is still installed, and considering the cold start issues plus voltage fluctuation codes, a discharged battery or end-of-life battery scenario is more likely than what I dealt with. The alternator overcharging pattern shown by your codes often happens when the battery terminals are corroded or the battery cells are failing. The charging system tries to compensate, leading to those high/low voltage readings. My suggestion would be to: 1. Get the battery load tested first 2. Have the battery terminals cleaned and checked 3. Test the alternator output This approach should cost less than the sensor replacement I needed. A new battery with installation typically runs 200-280€, while terminal cleaning and testing might only be 50€ if no other issues are found. The workshop should be able to diagnose this in about an hour, much quicker than my sensor replacement. If the battery tests confirm degradation, you could be back on the road the same day.

I appreciate the detailed responses. After comparing the symptoms and diagnostic information, I am convinced we are dealing with two different issues here. My car battery situation seems more straightforward than your sensor problem. Today I checked the battery manufacturing date stamp, definitely the original from 2023. The vehicle battery clearly shows signs of heavy drain during cold starts, and those P0562/P0563 codes strongly suggest a basic charging system problem. Will schedule an appointment to have the battery tested and likely replaced. Since battery charging issues can mask other electrical problems, I will also request a full charging system diagnostic to rule out alternator problems. Much cheaper than the 315€ sensor repair you experienced. Local shops quote around 250€ for a new battery with installation, which seems reasonable given the symptoms. Should be a quick fix compared to your sensor replacement. Thanks for helping me narrow down the problem. The voltage fluctuation patterns and error codes make more sense now in context of battery failure rather than sensor malfunction.