VW Battery Issues Causing Multiple Electrical Problems

Had a similar issue with a VW Golf 2013 last winter. As someone who has moderate experience working on cars, I first suspected a simple battery drain issue, but it turned out to be more complex. The symptoms were nearly identical, dimming lights, unusual error messages, and difficult starts. After my own attempts at checking the battery charging system failed, I took it to a workshop. Their diagnostic revealed a faulty battery sensor, which was causing incorrect readings and making the charging system behave erratically. The repair cost 315€ including parts and labor. Since the fix, all electrical systems have been working perfectly with no more warning lights or starting issues. The battery sensor plays a crucial role in modern vehicles by monitoring battery condition and controlling the charging system. To better assist with your situation, could you share: Have you checked the battery voltage? Are the problems constant or do they come and go? When was your last battery replacement? Do you notice these issues more during cold starts? A proper diagnosis would help determine if your Suran is facing the same battery sensor problem or if its something else in the electrical system.

Current mileage: 109381km Last service: 3 months ago Thanks for this detailed response. I checked the battery voltage yesterday, it reads 11.2V when the engine is off, which seems quite low. The problems started gradually but are now constant, especially during morning starts. The battery is actually the original one from 2011, which Im now realizing is probably well past its useful life. The symptoms got much worse after I accidentally left the interior lights on overnight last week. Your feedback about the battery sensor is helpful, I will get that checked too. But given the age of my battery and the clear signs of a discharged battery, I suspect a simple replacement might solve most of these electrical system issues. Would you recommend getting the alternator tested while checking the battery drain situation? I want to ensure the new battery wont get drained if theres an underlying charging problem.

Thanks for those additional details. Your 11.2V reading is a clear red flag, a healthy battery should show around 12.6V when the car is off. The fact that its the original 2011 battery combined with the recent deep discharge from the interior lights strongly suggests a heavily discharged battery thats reached end of life. On my Golf, I initially thought the alternator was the culprit too. Getting it tested is absolutely worth doing before installing a new battery. A faulty alternator can quickly drain a new battery, so its smart to verify the charging system is working correctly. The workshop found my alternator was fine, but they did a parasitic drain test that revealed a minor constant battery drain from a faulty trunk light switch. These small drains can compound the effects of a failing battery. Given your symptoms mirror my initial experience so closely, Id suggest: 1. Battery voltage test under load 2. Alternator output test 3. Parasitic drain check 4. Battery sensor diagnostic A new battery will likely resolve most issues, but confirming theres no underlying electrical system problem will prevent future battery failure. The complete test procedure cost me about 80€ but saved money long term by identifying all potential issues before replacement. Would you like details about specific testing procedures you could do at home before taking it to a shop?

Thanks, but I think I have enough information to proceed. The age of my battery combined with the low voltage reading and that overnight drain incident make it pretty clear I need a new battery. My local parts store offers free battery and alternator testing, so Ill start there before investing in a replacement. Based on your feedback, Ill have them check: Battery voltage under load, Alternator charging output, Battery terminals and connections, Basic parasitic drain test If they confirm its just a discharged battery thats past its service life, Ill go ahead with replacement. But if they spot any charging system issues or unusual drains, Ill get a proper diagnostic at a workshop first. Really helpful to know about potential battery sensor issues too, Ill keep that in mind if problems persist after installing a new battery. Thanks for helping me narrow down the most likely cause of my electrical system troubles.