## 3 EV Battery Chargers and Their Architectures
### Based on the Charger Installation
#### 3.2.1 On-Board Charger  
The battery of an EV has the capability to be recharged while still on the vehicle itself by establishing a connection to an external power source, such as a wall outlet. In this technology, the battery is commonly charged utilizing either direct current (DC) or alternating current (AC). In addition to home charging and recharging stations, it serves as a primary method for recharging an EV. On-board charging is a common practice for EVs in public parking lots and on roads equipped with charging infrastructure. EV batteries are charged through the utilization of on-board chargers. Each type of product/device/system, varying in size and power output, possesses its own unique set of advantages and disadvantages [62]. There are three primary types of on-board chargers that are commonly used: bidirectional chargers, AC chargers, and DC chargers. * AC Chargers: The AC charger is typically the most expensive and time-consuming type of on-board charger. They can only charge vehicles with a certain amount of capacity because they have a limited power output. On the plus side, AC chargers can be used with almost any kind of vehicle and are adaptable. * DC Chargers: Compared to AC chargers, DC chargers are significantly less expensive and typically offer quicker charging times. They can charge cars with larger batteries \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Power Flow** & **Power Level** & **Cost** & **Pros** & **Cons** \\ \hline Unidirectional & One-way electric & & & Less circuit complexity. & & G2V function does not support the smart grid function. \\ Unidirectional & energy flow & Level 1, Level & Lower cost. & & Compact size and less volume. & & Conduction loss in the diode bridge rectifier in PFC converter. \\ Charger & (basically, battery charging only). & & & & Long battery life. & & V2G techniques are not possible. \\ \hline Bidirectional & Two-way electrical energy flow and communication. & Expected only for Level 2. & High cost. & Low harmonics in input supply. & & Negative impact on the charger power density. \\  & & & & & & Battery life is low; frequent charging and discharging cycles. \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Comparative analysis of on unidirectional and bidirectional chargers. because they are typically more powerful. They are not adaptable, however, and they might not work with all kinds of vehicles. * Bidirectional Chargers: The most cutting-edge on-board charger, offering the highest power output and charging speed, are bidirectional chargers. The most versatile kind of charger, they can charge stationary batteries as well as EVs. However, they are also the costliest and most maintenance-intensive type of charger. In order to enhance the efficiency of on-board charging systems, researchers have devised multiple applications for on-board charging. On-board charging technology enables EVs to replenish their battery power while in motion. By leveraging this technology, the range of EVs can be extended, thereby eliminating the need for frequent charging stops. The system operates by converting the kinetic energy generated by the vehicle's movement into electrical energy. This electrical energy is subsequently stored in the vehicle's battery with the assistance of an on-board charger. The increasing popularity of this technology can be attributed to its ability to allow EVs to travel long distances without the need for frequent charging stops. Limitations of On-Board Chargers:
* Restricted Input Power: On-board chargers are normally limited to a maximum of 20A or 40 A, depending on the size of the car. This suggests that the charger can only receive a certain amount of power from the wall outlet. Due of this, charging the car quickly may be difficult, especially if you are using a low-amp outlet. * Limited Charging Speed: On-board chargers can only charge at a maximum rate of 6-8 kW, depending on the model. This means that it can take some time for the car to finish charging, especially if you are using a sluggish outlet.