Volkswagen ID.4: Classifying high-voltage batteries

Fundamentals of classifying high-voltage batteries

The installed high-voltage batteries are highly complex components and systems that could be affected during their service life by defects, failure and partial failure.

The high-voltage battery could be damaged in a road traffic incident.

The substances contained in high-voltage batteries are hazardous materials.

The state of the high-voltage battery impacts the following service requirements and workshop processes:

• Special qualification requirements of service employees EIP, HVT and HVE.
• Repairability of high-voltage battery
• Packaging and transport process for high-voltage batteries
• Quarantine and reporting processes to be carried out

Important

• To assess the hazard potential of the high-voltage battery, classify the high-voltage battery.

The high-voltage battery can be assigned to 3 states:

1. "NORMAL", not critical: no measures need to be taken.
2. "WARNING", critical: failure to observe the recommended measures may lead to fatal/serious injury.
3. "DANGER", dangerous: failure to observe the recommended measures will lead to fatal/serious injury.

Carry out assessment based on classification matrix.

Classification matrix

Assessment criteria:

Visual, sensory:

• No relevant mechanical damage.
• No fluid leaks.

Functional, electric:

• High-voltage battery can be diagnosed.
• No relevant entries in event memory.

Thermal:

• Temperature within tolerance.

Classification:

• NORMAL

Not critical: No measures have to be taken.

Fulfilment of ALL criteria results in classification "NORMAL".

Visual, sensory:

• Relevant mechanical damage, e.g. dent, crack, opening, defective seal.
• Corrosion damage.
• Pungent smell.

Functional, electric:

• High-voltage battery cannot be diagnosed.
• Relevant entries in event memory.

Thermal:

• Temperature outside tolerance

Classification:

WARNING

Critical: Failure to observe the recommended measures may lead to fatal/ serious injury.

Fulfilment of ONE criterion results in classification "WARNING"

Assessment criteria:

Visual, sensory:

• Fluid leak, suspected fluid in high-voltage battery system.
• Sparks, smoke or vapour.
• Signs of fire.
• Unusual noises inside the high-voltage battery, e.g.

  crackling or hissing.

• Mechanical damage with exposed, accessible contacts/ conductors.
• Accessibility of highvoltage battery for temperature measurements, e.g. due to missing or damaged body parts, surface temperature of high-voltage battery higher than 80ºC

Thermal:

• Temperature ≥ 80ºC.

Classification:

DANGER

Dangerous: Failure to observe the recommended measures will lead to fatal/ serious injury.

Fulfilment of ONE criterion results in classification "DANGER".

Matrix of measures

Classification:

NORMAL

Immediate measure:

• Not necessary.

Other measures and processes:

Repair according to Workshop Manual:

• Repair if necessary.

Intermediate storage/ quarantine:

• Original packaging
• Not stacked, flat on ground.
• Stored undercover outside and protected against rain.

Packaging and transport:

• Original packaging

Classification:

WARNING

Immediate measure:

• Quarantine
• Bring outside or into quarantine area/ quarantine cabinet.
•  Use PPE.

Other measures and processes:

Repair according to Workshop Manual:

• Implement disposal measures if repair not possible.
• Transfer to not critical status possible through repair.

Intermediate storage/ quarantine:

• Inform responsible party in accordance with reporting procedure.
• Move highvoltage vehicle/ highvoltage battery to suitable outside area/ space.
• Protect removed highvoltage battery against moisture.

Packaging and transport:

• Special transport crate required (may need to be dismantled).
• May only be packaged by trained personnel.

Carry out additional actions as instructed by HVE.

Classification:

DANGER

Immediate measure:

• Keep a safe distance.
• Observe highvoltage vehicle/ highvoltage battery.
• Have fire extinguishing equipment ready and at the first sign of fire immediately notify the fire service and evacuate the building.
• Do not inhale smoke/ gas.

  Wear mask.

• If the highvoltage battery has suffered mechanical damage with exposed, accessible contacts or conductors, do not touch the vehicle or the highvoltage battery.
• Quarantine highvoltage vehicle/ highvoltage battery if possible.
• Cordon off a large area and inform responsible party as per reporting procedure.
• Use PPE.

Other measures and processes:

Repair according to Workshop Manual:

• Not relevant.

Intermediate storage/ quarantine:

• Quarantine vehicle/ battery and call fire service if necessary.
• Observe highvoltage vehicle/ highvoltage battery.

Packaging and transport:

• Do not package.
• Do not transport.

Classification procedure

• The classification is software-based and carried out with the aid of "Guided Functions" via ODIS.
• Measured values of cell voltages and temperature sensors are collected, the event memory is interrogated, communication with the battery regulation control unit is checked.
• Classification can be carried out with the high-voltage battery fitted in the vehicle or removed.
• Only an HVE may reclassify the battery based on an assessment specific to the case.

Procedural diagram

Visual, sensory, function, electric and thermal assessment.

Criteria:

1. Signs of fire?
2. Sparks, smoke, vapour noticeable?
3. Noise from high-voltage battery, e.g. crackling?
4. Pungent smell?
5. Fluid leak or suspected fluid in high-voltage battery system?
6. Severe mechanical damage to high-voltage battery?
7. Temperature and cell voltage measurement?
8. Functional check of highvoltage battery?

Classification

• NORMAL (not critical)
• WARNING (critical)
• DANGER (dangerous)

Classification of high-voltage batteries with aid of ODIS

Special tools and workshop equipment required

• Diagnosis interface VAS 6154A - VAS 6154A-
• High-voltage diagnostics box -CN- - VAS 5581A

Assessing condition

With high-voltage battery installed:

• ⇒ Vehicle diagnostic tester Connect.
• Carry out classification with ⇒ Vehicle diagnostic tester.

Continued

With high-voltage battery removed:

• Connect high-voltage diagnostics box -CN- - VAS 5581Ausing vehicle-specific test adapters to communication connector of high-voltage battery.
• Switch on high-voltage diagnostics box -CN- - VAS 5581A- .
• Connect to ⇒ Vehicle diagnostic tester via diagnostics interface - VAS 6154A- or USB cable.
• Carry out classification with ⇒ Vehicle diagnostic tester.