how to tell if the battery is dying in Volkswagen Passat B8 (2015-2022)

Solution

1. Preparation

• Gather necessary tools: multimeter, battery tester, wrench set, cleaning solution, and safety goggles.
• Ensure the vehicle is parked on a flat surface and the engine is turned off.
• Disconnect the battery by removing the negative (-) terminal first.

2. Inspect Battery Terminals

• Sub-steps:
  1. Visually inspect the battery terminals for corrosion (white, ashy substance).
  2. If corrosion is present, clean the terminals with a mixture of baking soda and water.
     • Use a wire brush to remove corrosion.
     • Rinse with water and dry thoroughly.
  3. Tighten any loose connections on the battery terminals using a wrench.

3. Test Battery Voltage

• Sub-steps:
  1. Reconnect the negative terminal first, then the positive (+) terminal.
  2. Use a multimeter set to DC voltage.
  3. Place the red probe on the positive terminal and the black probe on the negative terminal.
  4. Read the voltage; a healthy battery should show around 12.6 volts or more.

4. Conduct Load Test

• Sub-steps:
  1. Connect the battery tester according to the manufacturer's instructions.
  2. Follow the prompts to apply a load equivalent to half the battery’s cold cranking amps (CCA) for 15 seconds.
  3. Observe the voltage drop; it should not drop below 9.6 volts during the test.

5. Replace Battery (if necessary)

• Sub-steps:
  1. If the battery fails the load test, remove it by disconnecting the negative terminal first, followed by the positive.
  2. Install the new battery by connecting the positive terminal first, then the negative.
  3. Ensure all connections are secure and clean, and check for tightness.