Demystifying Electric Vehicles: What is on board charger?

Discover the fundamentals of electric vehicle technology, including what is on board charger, unraveling the mysteries behind powering the future of transportation.

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Table of Contents

An onboard charger (OBC) is a crucial component in electric vehicles (EVs), tasked with converting AC power from the grid to the DC power that charges the vehicle’s battery pack. Understanding what is an onboard charger and its function in an electric vehicle can provide insights into how EVs harness external power sources effectively.

Exploring the differences between on board and off board chargers, the specifics of a 11kw triphase onboard charger, and the global trends in high-power onboard chargers for electric vehicles sheds light on the technological advancements in the field. This article aims to demystify the onboard charging process, detailing how onboard battery chargers work and their role within the broader EV charging ecosystem.

What is on board charger?

At the heart of electric vehicle (EV) technology, the onboard charger (OBC) plays a pivotal role in managing the charging process, ensuring that the vehicle’s battery is charged efficiently and safely. Here’s a closer look at how onboard chargers function and their significance in the EV ecosystem:

Conversion Process

The OBC converts alternating current (AC) from the grid into direct current (DC), which is suitable for charging the vehicle’s battery. This process involves two key stages:

  1. Power Factor Correction (PFC): Converts AC to DC while minimizing energy loss.
  2. DC/DC Conversion: Adjusts the DC output to the appropriate voltage and current levels for the battery.

Communication and Safety

  • The OBC communicates with both the vehicle controller and the charging station to determine the optimal charging parameters, such as the amount of current/power and the correct charging standard (e.g., SAE J1772 or CCS).
  • It incorporates various safety mechanisms to protect against overcharging, overheating, and electrical faults, ensuring a safe charging process.

Bidirectional Charging Capability

A unique feature of some OBCs is their ability to support bidirectional charging, meaning they can also convert DC power from the vehicle’s battery back to AC power. This functionality enables:

  1. Vehicle-to-Load (V2L): Powering external AC loads directly from the vehicle.
  2. Vehicle-to-Grid (V2G): Sending power back to the grid, providing energy storage solutions and potentially earning revenue for the vehicle owner.
  3. Vehicle-to-Vehicle (V2V): Charging another EV directly from the vehicle’s battery.

Understanding these aspects of onboard chargers illuminates their critical role in the broader context of EV technology and infrastructure, highlighting their contribution to the efficiency, safety, and versatility of electric vehicles.

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Unveil the essential role of on-board chargers in electric vehicles: what they are, how they work, and their impact on the future of automotive innovation

What is an on board charger? Let’s discuss types and characteristics

Electric vehicles (EVs) are equipped with onboard chargers (OBCs) that vary in their charging capabilities and characteristics, catering to the diverse needs of EV owners. Here’s a closer look at the types of onboard chargers and their distinct features:

Single-Phase vs. Three-Phase OBCs

  • Single-phase OBCs typically offer a charging capacity ranging from 7.2 kW to 11 kW. These chargers are suitable for home use where a three-phase electrical supply is not available.
  • Three-phase OBCs, on the other hand, have a higher capacity of up to 22 kW, enabling faster charging. They require a three-phase electricity supply, making them ideal for commercial or industrial settings.

Charging Levels

  • Level 1 Chargers: Utilize a standard 120 V AC outlet, taking 8 to 12 hours for a full charge.
  • Level 2 Chargers: Use a more powerful 240 V AC outlet, reducing charging time to 4 to 8 hours.
  • Level 3 Chargers (DC Fast Chargers): Directly supply DC power to the battery, significantly speeding up the charging process to just 30 minutes to an hour.

Future Trends

  • The industry is moving towards standardizing 11kW OBCs for battery electric vehicles (BEVs) and 6-8kW OBCs for plug-in hybrid electric vehicles (PHEVs).
  • DC charging capabilities are expected to become a standard feature in BEVs, with OEMs enabling charging capacities ranging from 50-250kW.
  • Premium models may offer up to 350kW+ DC charging, while mass-market BEVs will likely include both AC and DC charging options as standard, reflecting the increasing size of battery packs and the expansion of charging infrastructure.

Challenges and Advancements in Onboard Charger Technology

As electric vehicles (EVs) continue to evolve, the technology behind onboard chargers (OBCs) faces both challenges and significant advancements. The shift towards higher voltage charging infrastructure, particularly 800V batteries, marks a pivotal step in enhancing EV performance and reducing charging times. This is further complemented by the development of traction-integrated onboard chargers (iOBCs) that leverage the high-powered electronics of the EV for faster charging while stationary. The adoption of 800V platforms and traction iOBCs in numerous commercial and passenger EV models underscores the industry’s commitment to improving charging efficiency.

However, the transition to advanced charging technologies like the 11kW triphase onboard charger introduces complexities, particularly for home installations. These chargers necessitate a three-phase electricity supply, which is not standard in single-phase properties, thereby limiting their applicability. The cost associated with installing an 11kW charger, ranging between £1,200- £1,800 excluding infrastructure upgrades, presents another barrier. Moreover, the lack of standardized EV charging protocols and the need for uniform fast DC charging standards highlight the ongoing challenges within the industry.

Advancements such as the development of two-way onboard chargers (V2G) for electric and plug-in hybrid vehicles promise to revolutionize the market by enabling energy flow back to the grid. This, coupled with strategic enhancements from key industry players and the global proliferation of charging infrastructure, points to a future where EV charging is more accessible and efficient. Yet, utility upgrades, electricity rates, and the need for extensive infrastructure investment for curb-side charging remain significant hurdles to widespread EV adoption.

The Future of Onboard Charging and EV Technologies

The future of onboard charging and EV technologies is poised for significant advancement, driven by a blend of innovation, regulatory support, and market dynamics. Key developments include:

Off-Grid Solar Charging Infrastructure

  • Ideal for areas where traditional construction is prohibited.
  • Deployable without the need for digging or trenching.
  • Can be combined with onsite battery storage for enhanced portability.

NEVI Formula Program:

  • Aims to standardize EV charging in the U.S. with predictable standards and reliability requirements.
  • Most states are expected to initiate NEVI programs in 2023, with mass deployment anticipated in 2024.

Market Growth and Technological Advancements:

  • The high-power charger market is expected to see substantial growth, with projections indicating a CAGR of over 25% from 2021 to 2026.
  • Innovations in fast charging technologies promise to reduce charging times significantly, with some systems capable of delivering power levels exceeding 350 kW.

These advancements, coupled with increased public and private investment in charging infrastructure, are setting the stage for a transformative era in electric vehicle technology. The integration of renewable energy sources and the development of intelligent charging solutions are expected to further enhance the efficiency and sustainability of EV charging, making electric vehicles an increasingly viable and attractive option for consumers worldwide.

Difference between on board and off board charger

Understanding the distinction between onboard and offboard chargers is crucial for electric vehicle (EV) users to make informed decisions about their charging options. Here’s a concise comparison based on key aspects:

Location and Design Constraints

  • Onboard chargers are integrated within the EV, making them subject to size, weight, and power limitations. This results in compact, lightweight units with relatively lower power.
  • Offboard chargers, situated externally, face no such constraints, allowing for larger, more powerful designs.

Charging Process and Speed

  • Onboard chargers typically convert either single-phase 220V AC or three-phase 380V AC into DC, facilitating slower “trickle” charging suitable for overnight use.
  • Offboard chargers transform AC power into a controllable DC supply, enabling rapid “fast charging” by delivering large currents to quickly replenish a battery’s charge.

Component Composition and Impact on Battery Life

  • Comprising primarily a power circuit and control circuit, onboard chargers gently charge the battery, potentially extending its lifespan.
  • Offboard chargers include a more complex setup of power, control, metering units, and interfaces, with frequent fast charging sessions possibly shortening battery life.

This comparison underscores the trade-offs between the convenience of slow, anytime charging provided by onboard chargers and the speed of offboard chargers, which, while faster, may require more careful management of battery health.

What is a 11kw triphase on board charger

An 11kW triphase on board charger represents a significant upgrade over more commonly used 7kW chargers, offering a faster and more efficient charging experience for electric vehicle (EV) owners. Here are some key points to consider:

Charging Speed

An 11kW charger can deliver approximately 38-40 miles of range per hour of charging. This is nearly sixty percent faster than the 7kW chargers, which are more commonly found in residential settings. This enhanced charging capability means less time waiting for a full charge and more time on the road.

Installation Requirements

While the prospect of faster charging at home is appealing, it’s important to note that an 11kW charger requires a three-phase electricity supply. This type of supply is not standard in all homes and may necessitate an upgrade to the existing electrical infrastructure.

Comparison with 7kW Charger

  • 11kW Charger: Delivers 38-40 miles of range per hour, requires three-phase electricity.
  • 7kW Charger: Slower charging speed, compatible with standard home electrical systems.

Understanding the capabilities and requirements of an 11kW triphase on board charger is crucial for EV owners considering an upgrade to their home charging setup. While the faster charging speeds are a significant advantage, the need for a three-phase electrical supply may pose a challenge for some homeowners.

Function of on-board charger in electric vehicle

The function of an onboard charger (OBC) in an electric vehicle (EV) is multifaceted, playing a critical role in ensuring the vehicle’s battery is charged efficiently and safely. Below are the primary functions and requirements of an OBC:

Compliance with Grid Requirements

  • Supports both single-phase and three-phase operation
  • Ensures isolation from the power source
  • Meets Electromagnetic Compatibility (EMC) standards

Management of Charging Parameters

  • Controls the current and voltage at which the battery is charged
  • Adjusts charging parameters to extend the battery’s lifespan

Conversion of Power:

  • Converts AC power from a charging station or outlet into DC power
  • Enables the charging of the vehicle’s battery through this conversion process

This intricate process underscores the onboard charger’s vital role in bridging the gap between the power grid and the EV’s battery, ensuring that the vehicle is ready for use while optimizing battery health and longevity.

Global trends in high-power on-board chargers for electric vehicles

Addressing the barriers to electric vehicle (EV) adoption, it’s clear that upfront costs and infrastructure limitations play a significant role. Here are the key points to consider:

Upfront Costs:

  • Vehicle Expenses: The initial purchase price of EVs can be higher than their gasoline counterparts, partly due to the cost of onboard chargers and battery technology.
  • Charging Infrastructure: Installation of home charging stations or upgrades to existing electrical systems can add to the initial financial burden for potential EV owners.

Infrastructure Availability and Distribution:

  • Limited Charging Stations: The geographic distribution of public charging stations remains uneven, with urban areas typically better served than rural locations.
  • Infrastructure Investment: Significant investment in both the number and capacity of charging stations is required to support the growing number of EVs.

Safety and Connectivity for Micromobility:

  • Improving Safety: For users of electric bikes and scooters, the development of connected, high-quality bicycle and pedestrian facilities is essential for enhancing safety.
  • Infrastructure Integration: Thoughtful integration of these facilities into existing urban landscapes can encourage more people to consider micromobility options as a viable alternative to traditional vehicles.

These factors illustrate the complexities surrounding the global shift towards electric mobility, highlighting the need for continued innovation and strategic planning to overcome these challenges and foster wider EV adoption.

How does an on board battery charger work

We already know what an on-board charger is, but how does an on-board battery charger work? In the UK, the installation of electric vehicle (EV) chargers at residential locations is subject to certain limitations, primarily due to the electrical supply capacity. Most homes are equipped to handle a 7kW EV charger, which operates efficiently on a 32amp 240v single-phase electrical supply. This standard setup is adequate for the needs of the average EV user, ensuring a balance between charging speed and system compatibility.

We recommend visiting our Smart Integrated Modules (SIMs) section if you need to modernize the power source of the electric vehicles you manufacture.

Charger Options:

  • Hydra Zodiac 7kW: Ideal for domestic, residential, or workplace settings for a single EV.
  • Hydra Zodiac 22kW: Offers faster charging, suitable for environments with a three-phase electrical supply.

When considering the installation of a 7kW EV charge point, especially in scenarios where the available electrical supply is limited to 16amp, it becomes necessary to integrate a Dynamic Load Balancer. This device ensures the charging process does not overload the existing electrical infrastructure, safeguarding against potential hazards and ensuring efficient power management.

Furthermore, the Hydra Home App presents a user-friendly solution for managing the charging process. It allows users to adjust the charging load via the app, tailoring the charging activity to fit within the constraints of their electrical system and personal schedule. This flexibility is crucial for optimizing the charging process, especially in households with varying power consumption patterns.

The overall charging speed of an EV is influenced by several factors, including the capabilities of the charging station, the charging cable, and the onboard charger itself. It’s essential to recognize that the ‘weakest link’ in this chain dictates the maximum charging speed achievable. This interdependence highlights the importance of ensuring compatibility and efficiency across all components involved in the EV charging process.


What is an Onboard Charger in Electric Vehicles?

An onboard charger (OBC) is a crucial component in electric vehicles (EVs) that transforms the alternating current (AC) from an external power source into direct current (DC) to replenish the vehicle’s battery pack.

How Does an Onboard Charger Work in EVs?

An onboard charger operates by converting AC power from external sources, like residential outlets, into DC power, which is then used to charge the electric vehicle’s battery pack. This process is essential for recharging the EV’s battery.

How Do Onboard and Offboard EV Chargers Differ?

The primary difference between onboard and offboard EV chargers is their location and flexibility. Onboard chargers allow EV batteries to be charged anywhere an electrical outlet is available, offering convenience and portability. In contrast, offboard chargers, not limited by size and weight constraints, provide added flexibility and redundancy in power electronic converters.

What Benefits Do Onboard Chargers Provide?

If you’re wondering what an on-board charger is, you’ll likely also be interested in its benefits. Onboard chargers in electric vehicles come with several benefits, including the use of soft switching with LLC resonant converters, active power factor correction, and Vienna rectifiers for front-end rectification. These features collectively enhance the charging efficiency and minimize switching losses, making the charging process more effective and energy-efficient.

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