There are several types of onboard chargers available for EVs, each with its advantages and disadvantages. The type of on board charger used in an electric vehicle can greatly impact the vehicle's charging time and overall practicality for long-distance travel and it is important to carefully consider the trade-offs between cost, charging speed, and availability when selecting an onboard charger for an electric vehicle.

Level 1 On-Board Charger: They use a standard 120 V AC electrical outlet to charge an electric vehicle's battery and are often the slowest type of onboard charger, with a charging time of 8 to 12 hours. Advantages of level 1 onboard chargers include their low cost, wide availability, and compatibility with standard household electrical outlets. Disadvantages include their slow charging time, which can make them less practical for long-distance travel.

Level 2 On-Board Charger: They use a 240 V AC electrical outlet to charge an electric vehicle's battery and offer faster charging times than level 1 on-board chargers, with a charging time of 4 to 8 hours. Advantages of level 2 onboard chargers include their faster charging time, which makes them more practical for long-distance travel, and their compatibility with public charging stations. Disadvantages include their higher cost, the need for a dedicated charging station, and their potential for limited availability in some areas.

Level 3 On-Board Charger: They are also known as DC fast chargers and they use direct current (DC) to charge an electric vehicle's battery. They offer the fastest charging times, with a charging time of just 30 minutes to an hour. Advantages of level 3 onboard chargers include their fast-charging time, making them ideal for long-distance travel, and their compatibility with public charging stations. Disadvantages include their high cost, the need for a dedicated charging station, and their potential for limited availability in some areas.

Combined Charging System (CCS) On-Board Chargers: They use a combination of AC and DC charging to charge an electric vehicle's battery. They offer a balance of charging speed and cost, with a charging time of 1 to 4 hours. Advantages of CCS on-board chargers include their fast-charging time, compatibility with public charging stations, and lower cost compared to level 3 on-board chargers. Disadvantages include their potential for limited availability in some areas and their need for a dedicated charging station.

The current onboard charger have several advantages, including convenience, portability, efficient charging, and built-in safety features. Convenience is achieved by having the charger integrated into the device, eliminating the need for external charging equipment. Portability is also a key advantage, as onboard chargers are compact and can be easily moved from one location to another. They are designed to efficiently charge the battery, reducing charging time and extending the life of the battery. In addition, safety features, such as overvoltage protection, overcurrent protection, short circuit protection, and thermal protection, ensure that the battery is charged safely and efficiently.

However, onboard charger also have some disadvantages. One disadvantage is that they may not be as powerful as external chargers, meaning that charging times may be longer. In addition, onboard chargers are integrated into the device, so if the charger fails, the entire device may need to be replaced. Finally, onboard chargers can be more expensive than external chargers, as they require specialized components and design. Despite these limitations, onboard chargers are a popular choice for many applications due to their convenience, portability, and built-in safety features. 

The future of onboard chargers is promising, with many opportunities for improvement. One of the main areas of focus should be increasing the charging efficiency, which will reduce charging times and extend the life of the battery. The need for optimal space utilization and the trend towards miniaturization and lighter products will also drive the development of smaller and lighter onboard chargers. Additionally, the integration of wireless charging technology will make charging even more convenient and hassle-free. Another key area of improvement will be the use of intelligent charging algorithms, which will dynamically adjust charging parameters based on battery status and usage patterns, resulting in improved battery life. To enhance safety, new safety features, such as fire-resistant materials and improved insulation, will be developed. Onboard chargers can also be integrated with renewable energy sources, such as solar and wind power, making charging more sustainable and eco-friendly. Furthermore, the integration of multiple charging options, such as AC, DC, and wireless charging, will make onboard chargers even more versatile and convenient to use.