On Board Charger (OBC) in Electric Vehicles

What is an On-Board Charger (OBC)?

An on board charger (OBC) is the part of your EV that converts electricity from the power grid into a form your battery can use. In simple terms, it’s the middleman between the charging cable and the battery.

Most homes and public charging stations provide AC (alternating current) electricity, but EV batteries store DC (direct current) power. The OBC’s main job is to transform that AC power into regulated DC power and feed it safely into the battery.

Without an OBC, you wouldn’t be able to plug your EV into a regular wall outlet or Level 2 charger — the battery would never charge.

How Does an On Board Charger Work?

Here’s what happens behind the scenes every time you plug in your EV:

1. AC power enters the vehicle from the grid or charging station.
2. The on board charger converts that AC into DC using internal power electronics.
3. The OBC then controls the voltage and current supplied to the battery, ensuring it charges efficiently and safely.
4. The Battery Management System (BMS) works with the OBC to monitor battery health and optimize the charging process.

Most OBCs use power factor correction (PFC) to draw power more efficiently from the grid and minimize wasted energy. They also switch between constant current (CC) and constant voltage (CV) charging modes as the battery fills up — delivering fast charging at first, then tapering down to protect the battery as it nears full capacity.

Key Components Inside an OBC

• AC/DC Converter – Handles the AC-to-DC conversion.
• Power Factor Controller – Keeps things grid-friendly and efficient.
• DC-DC (LLC) Converter – Provides stable voltage for the battery.
• Communication Interfaces – Talk to the BMS and charging station to monitor safety.
• Safety & Isolation Circuits – Prevent overcharging, overheating, or electrical faults.

On Board Charger Simulation for Two-Wheeler Vehicles

Our On Board Charger Simulation for Two-Wheeler Vehicles is designed to analyze and optimize the efficiency, power conversion, and control strategies of charging systems used in electric two-wheelers. As electric mobility grows, the demand for compact, lightweight, and highly efficient on board charger electric vehicle solutions becomes essential.

This simulation focuses on:

• Efficiency Analysis: Evaluating AC-DC conversion, power factor correction, and thermal performance.
  
• Charging Algorithms: Supporting CC, CV, and adaptive charging strategies for different battery chemistries.
  
• Power Factor Correction: Ensuring compliance with grid standards and minimizing harmonic distortion.
  
• Real-Time Validation: Using HIL/PHIL platforms for testing under various grid and battery conditions before hardware deployment.

Benefits include faster development cycles, reduced prototype costs, improved safety, and optimized energy management. These insights are especially useful for scooters, motorcycles, and last-mile delivery vehicles that rely on integrated on board charger electric vehicle technology.

OBC Types and Charging Power

On board chargers come with different power ratings, usually between 3.7 kW and 22 kW for passenger cars:

• Single-phase OBCs (3.7–7.4 kW): Common in home charging setups.
• Three-phase OBCs (11–22 kW): Found in higher-end EVs, allow faster charging at public stations.

Remember: if your car only has a 7 kW OBC, it won’t charge faster even if you plug into a 22 kW station.

OBC vs. DC Fast Charging

It’s worth noting that DC fast chargers bypass the OBC entirely. Instead, they supply DC directly to the battery. This is why fast chargers can fill a battery much quicker , but they’re more expensive and require specialized infrastructure.

Most EV owners rely on their power on board charger for daily charging at home or work and use DC fast chargers only when needed.

Applications of On Board Chargers

On board chargers (OBCs) are crucial across diverse electric mobility solutions, well beyond passenger cars. Their adaptability and efficiency serve various vehicles and charging needs:

Electric Passenger Cars: An on board charger electric vehicle system enables safe, efficient home and public AC charging, supporting smart features like time-of-use tariffs and renewable energy integration.

Electric Two-Wheelers: Compact and lightweight chargers power scooters and motorcycles in urban areas, optimized for lower power and smaller batteries while ensuring reliability.

Commercial EV Fleets: Onboard chargers support fleet management and overnight charging for delivery vans, boosting durability and reducing downtime.

Public Transportation: Electric buses and trucks use higher-power OBCs for large batteries, combining AC charging with DC fast charging, while maintaining grid compatibility.

Battery Swapping & Micromobility: Smaller OBC units in swapping stations and e-bikes ensure quick charging and integrate with smart energy systems.

Vehicle-to-Everything (V2X): Advanced on board charger electric vehicle solutions enable bidirectional charging, allowing EVs to power homes, support grid stability, and share energy with other vehicles

Simulation Benefits

By simulating on board charger performance before physical prototypes, engineers can:

• Explore efficiency under real-world grid conditions.
• Validate power factor correction (PFC) and charging strategies.
• Optimize thermal performance and reduce energy losses.
• Test safety mechanisms and compliance with grid standards.
• Reduce development time and cost by identifying faults early.

This approach enables a smoother transition from design to deployment and ensures that final OBC hardware meets performance and safety goals.