Automotive Ev Tools

Automotive Ev Tools

5 skill files covering ev-tools domain for automotive software engineering.

Applicable Standards

• ASPICE Level 2/3 for software process
• ASPICE Level 3
• AUTOSAR 4.4
• AUTOSAR 4.4 for software architecture
• IEC 61851 EV charging systems
• IEC 63110 Management of EV charging infrastructure
• IPC-2221 PCB design standards
• ISO 12405 Lithium-ion battery testing
• ISO 15118 Vehicle-to-Grid communication
• ISO 26262
• ISO 26262 (for automotive variants)
• ISO 26262 ASIL-C/D for BMS safety functions
• ISO 6469-1 Electric safety
• ISO 6469-1 Electric vehicle safety
• OCPP 1.6J (JSON over WebSocket)
• OCPP 2.0.1 (ISO 15118 integration)
• SAE J2464 EV battery abuse testing
• UL 1973 Batteries for stationary applications
• UN ECE R100 Battery safety and crash testing
• UN ECE R100 Battery safety regulations
• USABC Battery Performance Goals
• VDA Battery System Standards

Use Cases

• EV battery pack architecture design
• Cell selection and benchmarking
• Module and pack mechanical layout
• Thermal management system design
• BMS integration and wiring harness
• Safety analysis (FMEA, FTA, abuse testing)
• Weight and cost optimization
• Modular BMS PCB design and layout
• bq76940/ISL94202 AFE integration
• MPPT solar charging integration
• ThingSet protocol communication
• Load management and DC/DC control
• EV charge point software development
• Central system (CSMS) integration
• Smart charging and load management
• OCPP 1.6J and OCPP 2.0.1 protocol implementation
• Charging session management and billing
• Open-source BMS software architecture
• Cell monitoring and balancing algorithms
• SOC/SOH estimation implementation

Topics Covered

Battery Modeling

• pybamm-battery-modeling

Bms Hardware

• libresolar-modular-bms

Bms Software

• openbms-integration

Charging Infrastructure

• ocpp-charging-protocol

Pack Design

• battery-design-studio

Constraints

• Backward compatibility with OCPP 1.6J for existing infrastructure
• Billing accuracy requirements (MID-certified meters)
• Certification costs for automotive production use
• Component availability for open-source BOM
• Computational performance for real-time model variants
• Cost target 0C before charge acceptance
• Cabin heat recovery to battery thermal loop

Safety Analysis

• FMEA (Failure Modes and Effects Analysis):
• Cell failures: Internal short, thermal runaway, venting
• BMS failures: Sensor faults, contactor weld, firmware bugs
• Thermal failures: Coolant leak, pump failure, blocked flow
• Mechanical failures: Module retention, connector loosening, vibration damage

• FTA (Fault Tree Analysis):
• Top event: Thermal runaway propagation to full pack
• Contributing events: Cell defect + overcharge + cooling failure
• Mitigation: Firewall between modules, early fault detection, contactor trip

• Abuse testing per SAE J2464:
• Mechanical: Crush, nail penetration, drop
• Electrical: Overcharge, over-discharge, short-circuit
• Thermal: Oven exposure, thermal shock
• Pass criteria: No fire or explosion

• Crash safety per UN ECE R100:
• Frontal, side, rear, pole impact crash simulations
• HV interlock integrity, post-crash isolation verification
• Physical barriers to protect battery from intrusion

Weight and Cost Optimization

• Mass breakdown:
• Cells: 60-70% of pack weight
• Module structure: 10-15%
• Pack enclosure: 10-15%
• BMS and wiring: 5-10%
• Thermal system: 5-10%

• Cost breakdown ($/kWh):
• Cells: 70-80% of pack cost
• Module assembly: 5-10%
• Pack integration: 5-10%
• BMS: 5-10%
• Thermal management: 3-5%

• Optimization strategies:
• Cell-to-pack (CTP) architecture: Eliminate modules, integrate cells directly
• Structural battery pack: Pack enclosure as load-bearing chassis component
• Standardized modules: Platform sharing across vehicle models
• Lightweighting: Aluminum vs steel, optimized ribbing, topology optimization

Approach

1. Concept phase: Define pack energy/power, voltage, package space
2. Cell benchmarking: Test candidate cells for performance, safety, cost
3. Preliminary design: CAD layout of modules and pack, thermal simulation
4. Detailed design: Drawings for enclosure, busbar, coolant plate, BMS integration
5. Prototype build: Assemble alpha pack, install in test vehicle
6. Validation testing: Thermal, vibration, crash, abuse, durability
7. Design refinement: Iterate based on test results
8. Production release: Final drawings, BOM, assembly process, quality plan

Deliverables

• Battery pack specification (energy, power, voltage, weight, cost, life)
• Cell selection report with benchmarking data
• CAD models (CATIA, SolidWorks) of module and pack
• Thermal simulation results (CFD, transient analysis)
• Electrical schematics (HV distribution, BMS wiring)
• Safety analysis (FMEA, FTA, abuse test reports)
• Bill of Materials (BOM) with cost estimate
• Manufacturing assembly instructions and test plan

Best Practices

• Design for manufacturing (DFM): Minimize manual assembly, automate welding
• Design for serviceability (DFS): Module replacement without full pack disassembly
• Design for recycling: Material separation, labeled plastics, reusable structure
• Concurrent engineering: Involve BMS, thermal, safety teams early
• Digital twin: Build simulation model in parallel with physical pack
• Benchmarking: Teardown competitor packs (Tesla, GM, VW) for best practices

Integration with Vehicle Development

• Packaging: Coordinate with vehicle design for underbody space, ground clearance
• Electrical: HV interlock loop, isolation monitoring, DC/DC converter
• Thermal: Integrate battery chiller with cabin HVAC system
• Crash: Collaborate with safety team on crash structures and intrusion barriers
• Diagnostics: CAN communication to instrument cluster for SOC/range display
• Charging: DC fast charge thermal constraints, preconditioning strategy

Tools and Software

• CAD: CATIA V5/3DX, SolidWorks for mechanical design
• CFD: ANSYS Fluent, Star-CCM+ for thermal simulation
• FEA: ANSYS Mechanical, Abaqus for structural and crash analysis
• Electrical: AutoCAD Electrical, Zuken E3.series for schematics
• Battery modeling: MATLAB/Simulink, PyBaMM for electrochemical simulation
• Cost modeling: aPriori, Boothroyd Dewhurst DFM for cost estimation

libresolar-modular-bms

Core Competencies

Expert in LibreSolar modular open-source battery management system, covering hardware design, firmware development, and system integration for automotive EV and stationary energy storage.

LibreSolar BMS Architecture

• Modular topology: Stackable boards for 3S to 15S per module, daisy-chained to 400S+
• AFE chips: TI bq76940 (5S), bq76930 (10S), bq76920 (15S), Renesas ISL94202
• STM32 microcontroller: STM32L452 or STM32G431 for low-power operation
• Communication: CAN, UART, I2C for multi-module systems
• ThingSet protocol: Standardized data model for battery parameters and control

Hardware Design Features

• PCB layout:
• 4-layer board with dedicated analog ground plane
• Kelvin sensing for accurate cell voltage measurement
• High-current traces (50A+) with thermal reliefs
• Creepage/clearance per IEC 60664 for HV isolation

• Cell monitoring:
• Differential voltage measurement (mV accuracy)
• Balancing FETs (100 mA passive balancing per cell)
• Temperature sensing via NTC thermistors (8 channels)
• External current sensor interface (hall effect or shunt)

• Protection circuits:
• High-side and low-side MOSFET drivers for main contactors
• Pre-charge resistor circuit for capacitor inrush limiting
• Fuse or circuit breaker coordination
• Reverse polarity protection on all connectors

• Power supply:
• Isolated DC/DC converter for microcontroller power
• LDO regulators for AFE chip supply
• Battery voltage range: 12V to 800V pack support

Firmware Features

• State machine: Idle -> Pre-charge -> Normal -> Fault handling
• SOC estimation: Coulomb counting with OCV calibration
• Balancing logic: Configurable thresholds and algorithms
• MPPT charging: Perturb & Observe algorithm for solar input
• Load management: DC/DC converter control, inverter enable/disable
• Data logging: Circular buffer with CAN/UART export
• Configuration: ThingSet commands for runtime parameter adjustment

ThingSet Protocol

• Data model: Hierarchical structure for battery parameters
• /battery/voltage, /battery/current, /battery/soc
• /cells/voltages, /cells/temperatures
• /config/limits/voltage_max, /config/limits/current_charge_max

• Transport layers: CAN, UART, LoRaWAN for remote monitoring
• Request/Response: JSON-style commands for diagnostics
• Pub/Sub: Periodic broadcast of telemetry data

MPPT Solar Charging

• Algorithm: Perturb & Observe with adaptive step size
• Input voltage range: 12V to 150V solar panel input
• Efficiency: >95% at rated power
• CC-CV transition: Constant current to constant voltage charging
• Temperature compensation: Adjust charge voltage by -3 mV/C/cell

Load Management

• DC/DC converters: Buck/boost control for 12V/24V/48V loads
• Inverter interface: Enable signal based on SOC and load demand
• Priority load shedding: Disconnect non-critical loads at low SOC
• Power limiting: Reduce output power when battery temperature high

Approach

1. Hardware Selection: Choose AFE chip based on cell count (bq76940 for 12S, ISL94202 for 15S)
2. PCB Design: Layout in KiCad with LibreSolar reference design as baseline
3. BOM Sourcing: Select automotive-grade components (AEC-Q100 for ICs, -40 to 125C rating)
4. Firmware Porting: Clone LibreSolar firmware repo, configure for hardware variant
5. Calibration: Measure voltage/current sensor gains and offsets
6. Integration: Connect to solar MPPT, DC/DC converter, CAN bus
7. Validation: Run charge/discharge cycles, verify protection triggers
8. Enclosure Design: IP65-rated housing for automotive/outdoor use

Deliverables

• KiCad PCB design files (.kicadpcb, .kicadsch) with Gerbers
• Bill of Materials (BOM) with Mouser/Digikey part numbers
• Firmware source code (C/C++ for STM32) with build instructions
• ThingSet configuration files (.yaml) for data model
• Assembly instructions and test procedures
• Enclosure CAD files (.step) with mounting brackets
• Validation test report (charge/discharge, protection, temperature)

Best Practices

• Open-source licensing: Hardware under CERN-OHL-P, firmware under Apache 2.0
• Community engagement: Contribute improvements back to LibreSolar GitHub
• Modular design: Keep modules under 15S for safety and repairability
• Thermal management: Heatsink for balancing FETs, airflow for high-current paths
• EMC compliance: Shielded CAN cables, ferrite beads, proper grounding
• Safety testing: Fault injection (over-voltage, over-current, short-circuit)
• Documentation: Schematic annotations, silkscreen labels, wiring diagrams

Integration with Automotive EV Systems

• CAN bus: Broadcast SOC/SOH to VCU using J1939 or custom DBC
• Charger interface: Pilot signal (J1772, CCS) for AC/DC charging
• Motor inverter: Current limit and enable signal
• Thermal system: Request coolant pump when cell temp > 40C
• Diagnostics: UDS protocol access via CAN for service tools

LibreSolar Ecosystem

• LibreSolar Charge Controller: MPPT solar charger with ThingSet
• LibreSolar Data Manager: Cloud-based monitoring dashboard
• LibreSolar DC Nanogrid: 48V DC distribution for off-grid systems
• Community forums: Active support on GitHub discussions and Discord

Safety Considerations

• Isolation monitoring: Detect pack-to-chassis faults
• Fusing strategy: Per-module fuses for parallel strings
• Thermal runaway detection: dT/dt monitoring with alarm
• Fail-safe shutdown: Open contactors on firmware watchdog timeout
• Field serviceability: Modular replacement without full pack disassembly

ocpp-charging-protocol

Core Competencies

Expert in Open Charge Point Protocol (OCPP) implementation for electric vehicle charging infrastructure, covering charge point firmware, central system integration, and smart charging orchestration.

OCPP Protocol Versions

• OCPP 1.6J (most widely deployed):
• JSON messages over WebSocket (secure wss:// or plain ws://)
• Core profile: Boot, heartbeat, authorize, start/stop transaction, meter values
• Smart charging profile: Charging profiles, composite schedules
• Reservation profile: Reserve charging connector
• Firmware management profile: Remote firmware updates

• OCPP 2.0.1 (emerging standard):
• Enhanced security with ISO 15118 Plug & Charge
• Device model for advanced configuration
• Improved smart charging with detailed power schedules
• Display messages for driver interaction
• Tariff and cost information
• Data transfer extensions

Charge Point Architecture

• Hardware components:
• Charging controller (STM32, NXP S32, Raspberry Pi)
• Power electronics (AC EVSE or DC fast charger)
• Energy meter (MID-certified for billing)
• RFID reader for user authentication
• Display and HMI (status LEDs, LCD/touchscreen)
• Connectivity (Ethernet, 4G LTE, WiFi)

• Software stack:
• OCPP client library (C++, Java, Python)
• WebSocket client with TLS/SSL
• Local authorization cache (RFID whitelist)
• Transaction logging and persistence
• Real-time clock and time synchronization (NTP)
• Watchdog and fault recovery

OCPP Message Flow

• Initialization:

1. BootNotification: Charge point registers with CSMS
2. CSMS responds with Accepted/Pending/Rejected + heartbeat interval
3. GetConfiguration: CSMS retrieves charge point settings
4. ChangeConfiguration: CSMS sets parameters (e.g., MeterValueSampleInterval)

• Authentication:

1. Authorize: Send RFID tag ID to CSMS
2. CSMS checks user account status, responds with Accepted/Blocked/Invalid
3. Local authorization: If offline, check cached ID list

• Charging session:

1. StartTransaction: Report connector ID, RFID tag, meter start value, timestamp
2. CSMS responds with transaction ID
3. MeterValues: Periodic energy/power measurements during charging
4. StopTransaction: Report meter stop value, stop reason, transaction data
5. CSMS responds with acknowledgment

• Smart charging:

1. SetChargingProfile: CSMS sends power limit schedule (kW vs time)
2. Charge point applies composite schedule from all active profiles
3. GetCompositeSchedule: Query effective charging limit
4. ClearChargingProfile: Remove expired or superseded profiles

• Firmware management:

1. UpdateFirmware: CSMS provides firmware URL and install time
2. Charge point downloads firmware, verifies checksum
3. FirmwareStatusNotification: Downloaded -> Installing -> Installed
4. Reboot and resume operation

Central System (CSMS) Integration

• Backend architecture:
• WebSocket server farm (Node.js, Spring Boot, Go)
• Database: PostgreSQL for transactions, MongoDB for device state
• Message queue: RabbitMQ or Kafka for async processing
• Load balancer: NGINX or AWS ALB for charge point connections
• Cache: Redis for session state and authorization lists

• Business logic:
• User management: Accounts, RFID cards, payment methods
• Tariff engine: Time-of-use pricing, demand charges, subscription plans
• Load management: Distribute available power across charge points
• Reporting: Energy delivered, utilization, revenue analytics
• Notifications: SMS/email for session start/stop, faults

• Third-party integrations:
• Payment gateways: Stripe, PayPal, credit card processing
• Roaming networks: Hubject, Gireve for cross-operator access
• Fleet management: API for fleet operator dashboards
• Grid operators: De

…

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: pangzhenying2025
• Source: pangzhenying2025/hermes-automotive-skills
• License: MIT

Install and usage instructions live in the source repository linked above.