# A Comprehensive Review of Developments in Electric Vehicles Fast Charging Technology
## 2 Fast Charging Techniques for Electric Vehicles
### Battery swapping  
Battery swapping addresses the issue of long charging times associated with traditional methods by allowing drivers to exchange depleted batteries for fully charged ones quickly. Typically taking just a few minutes, this process benefits businesses managing fleets and individuals on long trips, reducing downtime [80], as shown in Figure 4. At dedicated swapping stations, the EV's discharged battery is replaced with a fully charged one, supported by advanced automation and communication technologies ensuring safe and efficient operations [81]. The swapped-out battery is then recharged for future use. Stations accommodate various EV models and employ automated systems for alignment and connections [82]. Advantages include reduced charging times, convenience, and potentially lower battery degradation [83]. While battery swapping offers a faster alternative, challenges like standardization and infrastructure costs must be addressed for widespread implementation, especially as charging technologies evolve. Battery swapping charging provides a faster alternative to standard AC charging, although it necessitates locating a swapping station. While generally safe, standardized procedures and automated mechanisms further ensure safety during swapping. These stations are designed for repeated swaps and offer moderate weatherproofing to withstand various conditions. However, their integration with existing infrastructure relies on the availability of a network of swapping stations with spare batteries, which is currently limited. Compatibility is contingent upon EVs being equipped with compatible battery packs, limiting universal applicability. Battery degradation may occur slightly faster due to handling and thermal stress during swaps. Despite the advantages, expanding a swapping network can be slower than upgrading charging stations, highlighting the differences in the scalability and upgradability of these techniques. Nonetheless, battery swapping boasts a high efficiency, although some energy loss occurs during handling and charging/discharging cycles.  
Modular design in car manufacturing, especially with battery packs, presents a transformative opportunity for the industry. The concept of easily swappable battery packs alongside dedicated swapping stations could redefine the efficiency of networks and promote manufacturing adaptability. Recent advancements in assembly planning and Industry 4.0 technologies are making this modular approach feasible, potentially reshaping global production and factory flexibility in the automotive sector.  
Table 1 provides a comprehensive overview of the specifications of these advanced fast-charging techniques for EVs, including their advantages and comparative analyses. The table covers several criteria essential to the effectiveness and viability of fast-charging systems, including convenience, safety, durability, integration with infrastructure, compatibility, battery degradation, scalability/upgradability, and efficiency. These criteria evaluate user-friendliness, safety measures, long-term reliability, compatibility with existing infrastructure, impact on battery health, ability to handle increased demand, and energy conversion efficiency.  
Figure 4: Battery swapping system.