What Size Generator To Charge An Electric Car?

As electric vehicles (EVs) become more prevalent, the need for reliable charging solutions has grown. While public charging stations and home EV chargers are standard, there are scenarios where using a portable generator to charge an electric car can be necessary, such as during power outages or when traveling in remote areas. This blog post will delve into the specifics of what size generator is required to charge an electric car, providing detailed examples and practical advice.

Table of Contents

Understanding the Basics of EV Charging

Before diving into generator sizes, it’s essential to understand the basics of EV charging. Electric vehicles typically charge at three levels:

Level 1 Charging: This method uses a standard 120-volt outlet and is the slowest, providing 4-5 miles of range per hour.
Level 2 Charging: This method uses a 240-volt outlet, similar to that used for large household appliances. It can provide 20-30 miles of range per hour.
Level 3 Charging (DC Fast Charging): This method uses direct current and can charge an EV to 80% in about 30 minutes. However, due to the high power requirements, this method is not feasible with portable generators.

For the purpose of this blog, we will focus on Level 1 and Level 2 charging, as they are more practical with portable generators.

Check out Can You Charge an Electric Car with a Generator?

Generator Size for Level 1 Charging

Level 1 charging can be achieved with a relatively small generator. Most portable generators can handle this load since it uses a standard 120-volt outlet. The power requirement for Level 1 charging is typically around 1.5 kW (kilowatts).

Example Scenario: Level 1 Charging

Vehicle: Nissan Leaf
Battery Capacity: 40 kWh
Charging Power: 1.5 kW
Range Added per Hour: 5 miles

To fully charge a Nissan Leaf from empty using Level 1 charging, you would need approximately 27 hours (40 kWh / 1.5 kW = 26.67 hours). A portable generator with a continuous output of 2 kW would be sufficient.

Generator Size for Level 2 Charging

Level 2 charging requires more power and, consequently, a larger generator. The typical power requirement for Level 2 charging ranges from 6 kW to 7 kW.

Example Scenario: Level 2 Charging

Vehicle: Tesla Model 3
Battery Capacity: 75 kWh
Charging Power: 7 kW
Range Added per Hour: 30 miles

To charge a Tesla Model 3 from empty using Level 2 charging, you would need approximately 10.7 hours (75 kWh / 7 kW = 10.71 hours). A generator with a continuous output of at least 7 kW is required for this scenario.

Read Can a Portable Generator Charge an Electric Car?

Real-World Generator Examples

Small Portable Generator for Level 1 Charging

Generator: Honda EU2200i
Power Output: 2.2 kW
Weight: 47 lbs
Fuel Type: Gasoline

The Honda EU2200i is a popular choice for Level 1 charging. It provides sufficient power to charge most EVs at Level 1 and is lightweight and portable.

Larger Portable Generator for Level 2 Charging

Generator: DuroMax XP12000EH
Power Output: 9.5 kW (continuous), 12 kW (peak)
Weight: 224 lbs
Fuel Type: Dual Fuel (Gasoline/Propane)

The DuroMax XP12000EH can handle the power requirements for Level 2 charging, making it a suitable option for faster charging needs.

Check out Do Electric Vehicles Have Alternators?

Charging Time Comparison

Below is a table comparing the charging times for different generator sizes and charging levels:

Vehicle	Battery Capacity	Charging Level	Power Output	Range Added per Hour	Time to Full Charge
Nissan Leaf	40 kWh	Level 1	2 kW	5 miles	27 hours
Tesla Model 3	75 kWh	Level 2	7 kW	30 miles	10.7 hours
Chevrolet Bolt EV	66 kWh	Level 2	6 kW	25 miles	11 hours
Ford Mustang Mach-E	88 kWh	Level 2	7 kW	30 miles	12.6 hours

What Size Generator to Charge an Electric Car

Practical Considerations

Fuel Consumption

Fuel consumption is one of the critical factors to consider when using a generator to charge an EV. Larger generators consume more fuel, which can be costly and inconvenient.

For example, a generator like the DuroMax XP12000EH consumes about 1 gallon of gasoline per hour at 50% load. Therefore, charging an EV for 10 hours could require 10 gallons of gasoline.

Noise Levels

Generators can be noisy, which might not be ideal in residential areas or campgrounds. Inverter generators, like the Honda EU2200i, are generally quieter and more suitable for such environments.

Environmental Impact

Using a gas-powered generator to charge an electric vehicle somewhat defeats the purpose of driving an EV, which is to reduce emissions. However, in emergencies, it can be a practical solution. For a more environmentally friendly option, consider a solar generator, which may not provide sufficient power for Level 2 charging.

Conclusion

Charging an electric vehicle with a generator is entirely feasible, provided you choose the right size generator for your needs. For Level 1 charging, a small portable generator with a 2 kW output will suffice. For Level 2 charging, a larger generator with at least a 7 kW output is necessary. When selecting a generator, consider factors such as fuel consumption, noise levels, and environmental impact.

By understanding your EV’s charging requirements and matching them with the appropriate generator, you can ensure that you have a reliable backup charging solution, whether you’re dealing with a power outage or exploring off-grid locations.