2022 Volkswagen Passat Owners Manual - 12 V vehicle battery

12 V vehicle battery

 Introduction

The 12-volt vehicle battery is a component of the electrical system and serves to supply energy to the vehicle.

You may only perform procedures on the electrical system yourself if you are familiar with the necessary procedures and the general safety precautions, and if the correct equipment and operating fluids and suitable tools are available. Work performed incorrectly can result in serious injuries ⇒ . Have all work performed by suitably qualified professionals. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Information about warning and indicator lights can be found in the troubleshooting section at the end of the chapter ⇒ Troubleshooting.

12 V vehicle battery location

The 12-volt vehicle battery may be located in the electric motor compartment or behind a cover in the luggage compartment, depending on vehicle equipment.

Detailed warnings for the 12 V vehicle battery

 Always wear eye protection.Battery acid is highly corrosive. Always wear protective gloves and eye protection. Fire, sparks, open flame, and smoking are forbidden.A highly explosive mixture of gases forms when charging the 12 V vehicle battery.Always keep children away from battery acid and the 12 V vehicle battery.Always heed the Owner's Manual.

WARNING

Performing work on the 12 V vehicle battery and the electrical system can cause serious injuries, fires, or electric shocks. Always read and heed the following warnings and safety precautions before performing any procedures:

• Before performing any work on the 12 V vehicle battery, switch off the ignition and all electrical equipment and disconnect the 12 V battery negative cable.

• Always keep children away from battery electrolyte and the 12 V vehicle battery.

• Always wear eye protection and safety gloves.

• Battery acid is highly corrosive. It can burn skin and cause blindness. When handling 12 V vehicle batteries, always protect your hands, arms, and face from spraying battery acid.

• Do not smoke while working and never work near open flames or sparks.

• Avoid creating sparks when working with wires and electrical equipment or when discharging static electricity.

• Never short circuit the battery terminals.

• Never use a damaged 12 V vehicle battery. The 12 V vehicle battery may explode. Replace a damaged 12 V vehicle battery immediately.

• Never use a frozen 12 V vehicle battery. A drained 12 V vehicle battery can freeze at temperatures around 32 °F (0 °C). Replace the 12 V vehicle battery immediately.

• For vehicles with the 12-volt vehicle battery in the vehicle interior, ensure that the degassing hose is connected to the 12-volt vehicle battery correctly. The degassing hose must always be connected to the negative terminal side of the 12-volt vehicle battery. If there is an opening on the positive terminal side of the 12-volt vehicle battery, it must always be capped.

WARNING

California Proposition 65 Warning

• This product can expose you to chemicals including lead and lead components, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

NOTICE

UV rays can damage the battery housing.

• Do not expose the 12 V vehicle battery to direct sunlight for a long period of time.

NOTICE

The 12 V vehicle battery could “freeze” and be destroyed.

• Protect the 12 V vehicle battery against freezing temperatures if the vehicle is parked for long periods of time.

After starting the engine when the 12-volt vehicle battery is severely drained or when it has been replaced or jump-started, the system settings (time, date, personal convenience settings, and programming) and user profiles may be changed or erased. Check and correct the settings after the 12 V vehicle battery is sufficiently recharged.

Checking the 12 V vehicle battery acid level

 Please read the introductory information and heed the Warnings and Notice ⇒ andSafety precautions for working in the engine compartment.

Check the acid level of the 12 V vehicle battery regularly if mileage is high, in countries with warm climates, or if the 12 V vehicle battery is old. Otherwise, the 12 V vehicle battery is maintenance-free.

The acid level of 12 V vehicle batteries labeled    cannot be checked for technical reasons. To have the 12-volt vehicle battery checked, contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Preparations

1. Prepare the vehicle for work in the engine compartment ⇒ In the engine compartment.

2. Open the hood ⇒ Opening and closing the hood.

Checking the battery acid level (12 V vehicle batteries with window)

Fig. 146 Window on the top of the 12 V vehicle battery (general example).

1. Depending on the vehicle equipment, an additional bracket must be removed to see the viewing window. An additional tool that is not available in the vehicle tool kit is required to do this.

2. Make sure there is enough light to clearly see the color indicator in the circular window on the top of the 12 V vehicle battery (arrow)  fig. 146. Never use open flames or smoldering objects to provide light.

The color indicator in the circular window changes depending on the acid level in the 12 V vehicle battery.

Light yellow or colorless

The 12 V vehicle battery acid level is too low. Have the 12 V vehicle battery checked and/or replaced by an authorized Volkswagen dealer or authorized Volkswagen Service Facility. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Black

The 12 V vehicle battery acid level is OK.

WARNING

• Always wear eye protection and safety gloves.

• Battery acid is highly corrosive. It can burn skin and cause blindness. When handling 12 V vehicle batteries, always protect your hands, arms, and face from spraying battery acid.

• Never tilt the 12 V vehicle battery. Acid can leak out of the vent openings and can cause chemical burns.

• Never open a 12 V vehicle battery.

• If battery acid comes into contact with the skin or eyes, rinse the affected area immediately with cold water for several minutes. Then consult a doctor immediately.

• Consult a doctor immediately if battery acid is swallowed.

Charging, replacing, disconnecting, or connecting the 12 V vehicle battery

 Please read the introductory information and heed the Warnings and Notice ⇒ andSafety precautions for working in the engine compartment.

If you suspect that the 12 V vehicle battery is damaged or malfunctioning, see suitably qualified professionals to have the 12 V vehicle battery checked. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Charging the 12 V vehicle battery

The 12 V vehicle battery should be charged by suitably qualified professionals because the 12 V vehicle battery that is installed at the factory requires a charging process where the voltage is limited ⇒ . Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Replacing the 12 V vehicle battery

The 12 V vehicle battery is designed to fit the location where it is installed and is equipped with safety features. If a 12 V vehicle battery needs to be replaced, have the replacement part fitted by qualified professionals. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility. Check with qualified professionals to find out the component information regarding size and the required maintenance, performance, and safety features. They must possess the necessary technical documentation and equipment. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility. The vent opening on the 12 V vehicle battery must always be located on the negative terminal. The vent opening on the positive terminal side must be sealed.

Only use a maintenance-free 12 V vehicle battery that conforms to the TL 825 06 and VW 7 50 73 standards. These standards must be from October 2014 or later.

Always have the 12 V vehicle battery replaced by qualified professionals because the vehicle electronics must be adapted as part of the replacement. In addition, the battery parameters for functional safety can only be determined with the OEM battery. Only qualified professionals have the necessary equipment to perform the adaptation and have access to the correct replacement batteries. Using unsuitable batteries may invalidate the operating license.

Disconnecting the 12 V vehicle battery

If the 12 V vehicle battery must be disconnected from the vehicle electrical system, note the following:

1. Switch off all electrical equipment and the ignition.

2. Unlock the vehicle before disconnecting the battery. Otherwise, the anti-theft alarm system will be triggered.

3. Disconnect the negative cable first, and then the positive cable ⇒ .

Connecting the 12 V vehicle battery

1. Switch off all electrical equipment and the ignition before reconnecting the 12 V vehicle battery.

2. Connect the positive cable first, and then the negative cable ⇒ .

Various indicator lights may turn on after connecting the 12 V vehicle battery and switching the ignition on. They will turn off after driving a short distance at a speed of approximately 10 - 12 mph (15 - 20 km/h). If the indicator lights do not turn off, see an authorized Volkswagen dealer or authorized Volkswagen Service Facility to have the vehicle checked.

If the 12 V vehicle battery was disconnected for a long period of time, the next scheduled maintenance may not display correctly or it may not be calculated correctly ⇒ Service interval display. Follow the maximum permissible maintenance interval ⇒ Maintenance.

Vehicles with Keyless Access⇒ Keyless Access: If the ignition cannot be switched on after connecting the 12 V vehicle battery.

1. Lock and unlock the vehicle from the outside.

2. Try to switch the ignition on again.

3. If the ignition will not switch on, contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Automatic equipment deactivation

If the 12 V vehicle battery is under a heavy load, the intelligent power management will automatically begin certain measures to prevent the 12 V vehicle battery from draining:

• The idle speed will be increased so that the alternator delivers more power.

• If necessary, equipment that uses a lot of power will have its performance limited or will be switched off.

• The power supply to the 12 V socket and the cigarette lighter will be interrupted temporarily when the engine is started.

The power management cannot always prevent the 12 V vehicle battery from being drained. For example, the battery could be drained if the ignition is left on for long periods of time when the engine is stopped or if the vehicle is parked for long periods of time with the parking lights on.

12 V vehicle battery draining

• If the vehicle is parked for long periods of time without running the engine, especially if the ignition is on.

• If electrical equipment is used when the engine is stopped.

WARNING

Securing the vehicle battery incorrectly or using the wrong 12 V vehicle battery can cause short circuits, fires, and serious injuries.

• Always use maintenance-free and leak-proof 12 V vehicle batteries that have the same characteristics, specifications, and dimensions as the 12 V vehicle battery that was installed at the factory.

WARNING

A highly explosive mixture of hydrogen gas can form when charging the 12 V vehicle battery.

• Only charge 12 V vehicle batteries in well-ventilated areas.

• Never charge a frozen or thawed 12 V vehicle battery. A drained 12 V vehicle battery can freeze at temperatures around 32 °F (0 °C).

• Always replace the 12 V vehicle battery if it freezes.

WARNING

Cables that are connected incorrectly can cause a short circuit.

• Connect the positive cable first and then the negative cable.

NOTICE

• Never connect or disconnect the 12 V vehicle batteries when the ignition is on or the engine is running. Never use a 12 V vehicle battery that does not conform to the vehicle specifications. The electrical system or electrical components could be damaged and electrical malfunctions could result.

12 V vehicle batteries can contain toxic substances such as sulfuric acid and lead. Dispose of 12 V vehicle batteries correctly.

Battery acid can pollute the environment. Collect spilled battery acid and dispose of it correctly.

Troubleshooting

 Please read the introductory information and heed the Warnings and Notice ⇒ andSafety precautions for working in the engine compartment.

 12 V vehicle battery

The red warning light turns on. The following message is displayed: 12 V battery is not charging. Safely park the vehicle.

Do not continue driving!.

The 12-volt vehicle battery is not being charged while driving.

1. Stop the vehicle as soon as it is safe to do so.

2. Turn off electrical equipment that is not needed.

3. Inform a suitably qualified professional. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

4. Have the electrical system inspected.

 12 V vehicle battery

The red warning light turns on. The following message is displayed: Error: 12 V power supply. Safely stop the vehicle. Consult Owner's Manual.

Do not continue driving!.

There is a fault in the 12-volt vehicle electrical system.

1. Stop the vehicle as soon as it is safe to do so.

2. Inform a suitably qualified professional. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

3. Have the electrical system inspected.

 12 V vehicle battery

The yellow indicator light turns on. The following message is displayed: Error: 12 V power supply. Please visit workshop..

There is a fault in the 12 V power supply.

1. Contact a suitably qualified professional. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

2. Have the electrical system inspected.

 12 V vehicle battery

The yellow indicator light turns on. The following message is displayed: Error: 12 V battery. Restart not possible. Service vehicle!

The connection between the 12 V vehicle electrical system and the 12 V vehicle battery is malfunctioning.

1. Contact a suitably qualified professional. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

2. Have the electrical system inspected.

If the engine is turned off in this situation, it cannot be restarted. Jump-start the vehicle if necessary ⇒ Jump-starting or contact an authorized Volkswagen dealer or authorized Volkswagen Service Facility. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

 12 V vehicle battery

The yellow indicator light turns on. The following message is displayed: Error: 12 V battery diagnosis. Please service the vehicle..

The system for monitoring the 12-volt vehicle battery is malfunctioning.

1. Contact a suitably qualified professional. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

2. Have the electrical system inspected.

 12 V vehicle battery

The yellow indicator light turns on. The following message is displayed: Please replace the 12 V battery. Service vehicle.

The 12-volt vehicle battery has almost reached the end of its service life.

1. Contact a suitably qualified professional. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

2. Check the 12-volt vehicle battery and have it replaced if necessary ⇒ Charging, replacing, disconnecting, or connecting the 12 V vehicle battery.

 12 V vehicle battery

The yellow indicator light turns on. The following message is displayed: Please have the 12 V battery checked. Service vehicle..

The connection between the 12 V vehicle electrical system and the 12 V vehicle battery is malfunctioning.

1. Contact a suitably qualified professional. Volkswagen recommends contacting an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

2. Have the electrical system inspected.

 12 V vehicle battery

The yellow indicator light turns on. The following message is displayed: The 12 V battery is low. Have it recharged by an authorized Volkswagen dealer or authorized Volkswagen Service Facility.

Poor charge acceptance of the 12-volt vehicle battery, caused, for example, by low temperatures.

1. Drive a short distance so that the 12-volt vehicle battery can be recharged.