Why We Cant Simply Plug 10 Chargers into an Electric Car for Faster Charging

Why We Can't Simply Plug 10 Chargers into an Electric Car for Faster Charging

In the world of electric vehicles (EVs), the concept of charging speed is a central topic of discussion. It is often misunderstood that plugging multiple chargers into an electric car can significantly boost the charging rate. This article explores the reasons why this isn't possible and discusses the factors that limit EV charging speed.

Understanding the Limits of Multiple Chargers

The idea of connecting multiple chargers to an electric motorcycle or a specialized vehicle like the Zero FXS seems valid, as it can indeed increase charging speed. This is due to the unique design of the motorcycle's charging system, which includes an internal charger and the ability to connect additional external chargers via a special socket on the battery bus. However, this method is not universally applicable to all electric vehicles.

The Uniqueness of the Zero FXS

The Zero FXS is a special case where multiple chargers can be connected to achieve faster charging. This is because the motorcycle has both an internal charger with an IEC socket like a PC and a special socket on the battery bus designed to accept a Y-cable for an external charger. The result is that the charging speed can be significantly increased by connecting up to three external chargers. Using one external charger, the charging process is about 3 times faster than using the internal charger alone.

Convenience and Standardization in Electric Vehicles

Most modern electric vehicles have only one charging socket, typically a J1772 connector. While it is convenient to have a single standard, it limits the ability to use multiple chargers for faster charging. For instance, despite the SR and larger models having a normal J1772 connector, they do not support multiple chargers. The design of the J1772 connector simply does not accommodate additional charging inputs beyond the single port.

Historical Perspective: Older Vehicles

Some older electric vehicles, such as milk floats or forklift trucks, may have been designed to handle multiple external chargers directly to the battery. However, this is uncommon in modern electric vehicles due to safety and design constraints.

The Role of Battery Cooling in Fast Charging

One of the critical factors that limit the charging speed of electric vehicles is the battery's cooling system. High charge rates can generate significant heat within the battery cells, which can be detrimental to their performance and longevity. Companies like Tesla have addressed this issue by using liquid cooling systems between smaller battery cells. This advanced cooling system allows for faster charging rates, maximized at up to 250 kW, and the design of their connector was optimized for this purpose.

Tesla's Innovations in Battery Cooling

Tesla's approach to battery cooling is one of the standout features in the EV market. Their use of smaller battery cells with liquid cooling between them ensures that heat is efficiently managed, allowing for faster charging speeds. Despite these advancements, other vehicles still face limitations due to the chemistry of their batteries and the potential for heat buildup.

Practical Considerations for Home Charging

For most home users, the inconvenience of multiple chargers is outweighed by the benefits of faster charging. However, solving the practical challenges of home wiring requires a custom-designed double charger. Additionally, with the majority of EVs not being fully drained daily, the need for extremely fast charging is minimal, and charging overnight at home is often sufficient.

For those looking to optimize charging time, installing a standard EVSE (Electric Vehicle Supply Equipment) connector is a more practical solution. These connectors are designed to handle the typical charging needs of most EV owners, ensuring safe and efficient charging without the added complexity of multiple chargers.

Current Charging Plug Capabilities

The limitations on charging speed are not related to the plug itself. For instance, the "old" European Type 2 connector is designed to handle up to 100 kW charging. However, most EVs can only support this level of charging for a short period, typically during the first few minutes of charging on a completely empty battery. The charge current drops rapidly as the battery fills up. Therefore, even with the highest-capacity Type 2 connector, most EVs will only see charging rates of around 100 kW on average.

The new CCS (Combined Charging System) plug, capable of 350 kW charging, is currently beyond the capabilities of any production EV. This discrepancy highlights the current technological limitations and the focus on improving battery chemistry and cooling systems rather than solely relying on better connectors.

Conclusion

The seemingly simple solution of plugging multiple chargers into an electric car is fraught with limitations. The primary factors limiting charging speed are the battery's inherent capabilities and its cooling system. While newer innovations like Tesla's advanced battery cooling can achieve faster charging rates, the limitations of standard charging connectors and the practical considerations of home use make the need for multiple chargers unnecessary for most electric vehicle owners.