why does my Volkswagen Golf MK7.5 (2020-Present) battery die overnight when car is off

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, wire brush, battery terminal cleaner.
• Disconnect the negative terminal of the battery to ensure safety.

2. Battery Inspection and Replacement

• Inspect Battery:
  • Clean any corrosion from battery terminals using a wire brush and battery terminal cleaner.
  • Check the date of manufacture on the battery; if older than 3-5 years, consider replacement.
• Replace Battery (if necessary):
  • Remove the battery hold-down bracket using a socket set.
  • Lift the battery out carefully and replace it with a new battery of the same specifications.
  • Reinstall the hold-down bracket and ensure the terminals are tightened securely.

3. Address Parasitic Draw

• Identify the Source:
  • With the multimeter connected in series, pull fuses one by one to identify which circuit is causing the draw.
  • Once identified, inspect the components connected to the faulty circuit for issues such as shorts or malfunctions.
• Repair or Replace Faulty Component:
  • Repair wiring as necessary or replace any faulty components (e.g., modules, switches).

4. Reconnect Battery and Test System

• Reconnect the negative battery terminal.
• Start the vehicle and check that all electrical components are functioning correctly.