EV Onboard Charger Repair, 2 days

Training Course: EV Onboard Charger (OBC) Repair

Focused on BYD and NETA Only

Duration: 2 Days (Approx. 6–7 hours/day)
Format: 30% Theory | 70% Hands-on Practice
Level: EV Technicians, Repair Shops, Engineers, Electronics Technicians

? Course Objectives

• Understand the structure and operating principles of EV Onboard Chargers (OBC) used in BYD and NETA

• Diagnose common charging issues: No charge / Slow charge / Charging interruption

• Perform electrical measurements and fault isolation at component level

• Repair OBC units practically to reduce full-unit replacement cost

?️ Course Structure (2 Days)

? DAY 1: System Understanding & Fault Diagnosis

1. Overview of EV AC Charging System

   • AC Charging Path: EVSE → OBC → HV Battery

   • Design differences between BYD and NETA OBCs

2. Internal Architecture of the Onboard Charger

   • EMI Filter

   • Rectifier

   • PFC (Power Factor Correction)

   • Isolated DC/DC Converter

   • Control & Communication Board

3. Essential Electrical Specifications

   • Input: 220–240 VAC

   • DC Bus: 350–420 VDC

   • Battery Output

   • Auxiliary 12V / CAN / Enable Signals

4. Common OBC Failure Symptoms (BYD / NETA)

   • Plugged in but no charging

   • Charging starts then stops

   • Low or unstable charging current

   • Vehicle or app error notifications

5. Fault Code (DTC) Interpretation

   • Common OBC-related error codes in BYD and NETA

   • Communication relationship: OBC ↔ BMS ↔ VCU

6. Professional Diagnostic Workflow

   • Visual inspection → Electrical measurement → Block isolation → Repair decision

?️ DAY 2: Measurement Techniques & Hands-on Repair

1. High-Voltage Safety Procedures

   • Lock-out / Tag-out

   • DC Bus capacitor discharge

2. OBC Disassembly & Board Separation

   • Power Board

   • Control Board

3. Key Measurement Points (BYD / NETA)

   • AC Input

   • PFC MOSFET / IGBT

   • DC Bus Capacitors

   • Transformer / Isolated Section

   • Gate Drive / PWM Signals

4. Diagnostic Tools for EV Repair

   • Multimeter (Diode / Resistance / LoZ Mode)

   • Component Tester

   • Oscilloscope (PWM, ripple, noise analysis)

5. Frequently Failed Components

   • MOSFET / IGBT

   • Diodes / Bridge Rectifiers

   • Electrolytic Capacitors (bulging / degraded)

   • Shunt Resistors / Current Sensors

   • Gate Driver ICs / Power Supply ICs

6. Practical Workshop

   • Real faulty OBC case studies (BYD / NETA)

   • Component-level repair practice

   • Post-repair testing (bench test & vehicle-level concept)

? What Participants Will Receive

• OBC troubleshooting flowcharts (BYD / NETA)

• Symptom → Measurement Point → Repair Action tables

• Electrical reference values & signal guides

• Repair vs replacement decision criteria

• Confidence to accept real-world OBC repair jobs

?‍? Target Participants

• EV repair shops

• EV technicians & electricians

• Electronics repair specialists

• OBC remanufacturing or spare-parts professionals

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