Can You Charge a Tesla With a Generator? Breaking Down the Possibilities

Introduction – Charge Tesla With Generator

The short answer is yes, but it takes a really long time. As a Tesla owner invested in cutting-edge technology, you may find yourself pondering the feasibility of charging your electric vehicle (EV) using a generator. This intersection of traditional power sources with the modern marvel of electric vehicles introduces a unique set of challenges and solutions, particularly the issue of AC versus DC power compatibility. Read on to find out how long it takes!

A stable AC source is safer

Charging Tesla With a Generator

Charging a Tesla with a generator is indeed feasible, but it requires a specific type of generator: an inverter generator. Tesla vehicles, like all electric vehicles, are designed to charge using AC power, which is then converted to DC within the vehicle for battery storage. Most generators produce AC power, but not all deliver the clean, stable power required by sensitive electronics like those in a Tesla. This is where an inverter generator, such as the Honda EU2200i, becomes vital.

Review: Honda EU2200i

The Honda EU2200i is renowned for its clean and stable power output, akin to what you’d receive from household electrical outlets or dedicated EV charging stations. Weighing just 47 pounds, it’s notably portable and offers 2200 watts of starting power and 1800 watts of running power, making it well-suited for the delicate task of EV charging. Beyond its power quality, the EU2200i boasts impressive fuel efficiency, capable of running for 4 to 9.6 hours on a full tank, depending on the load. Its built-in oil alert and circuit protection features further ensure the safety of both the generator and your Tesla during charging.

Understanding Charging Times

Before discussing the advantages and disadvantages of charging a Tesla with a generator, let’s delve into the specifics of what charging times can be expected. Using a Honda EU2200i as an example, we calculate the time required to charge a Tesla to half of its maximum battery capacity.

Assuming a mid-range Tesla with a 75 kWh battery capacity, charging to half capacity means needing approximately 37.5 kWh. The Honda EU2200i offers a running power of 1.8 kW. However, when accounting for the efficiency of the charging process (approximately 85%), the effective power available for charging is reduced to 1.53 kW. Based on these figures, charging a Tesla to half capacity would take:

Tesla Battery Capacity

Tesla models have various battery capacities, typically ranging from about 50 kWh for standard range versions to over 100 kWh for larger or performance models. For this calculation, let’s assume a mid-range battery capacity of 75 kWh.


The goal is to charge to half capacity, which is 75 kWh/2 or 37.5 kWh.

Honda EU2200i Generator Output

  • Running Power: 1,800 watts or 1.8 kW.
  • Voltage: 120V.

Charging Efficiency

The efficiency of AC to DC conversion for charging a Tesla can vary but typically ranges around 85% to 90%. For this calculation, we’ll use an efficiency rate of 85%.


  1. Power Available for Charging: Since the generator provides 1.8 kW and assuming an efficiency rate of 85%, the effective power available for charging the battery is 1.8 kW × 0.85 = 1.53 kW.
  2. Time to Charge to Half Capacity: To calculate the time required to charge to half capacity, we divide the target capacity by the effective power available for charging.

Time = Target Capacity divided by Effective Power, which is written as 37.5 kWh divided by 1.53 kW.

Let’s compute this.

To charge a Tesla battery to half its capacity (assuming a 75 kWh battery) using a Honda EU2200i generator, it would take approximately 24.5 hours. This estimate is based on the generator’s effective power output of 1.53 kW after accounting for an 85% charging efficiency.

Time=37.5 kWh divided by 1.53 kW≈24.5 hours.

This calculation highlights the significant time investment required to achieve even a 50% charge using a portable generator, underscoring the importance of considering other charging options for regular use.

The Pros and Cons

We learned two things. First, the specs on the generator and the Tesla means that yes, its possible to charge a Tesla using an external gas generator. Second, the time to charge to half max capacity of the battery using a standard 120V generator is 24 hours. Utilizing a generator for Tesla charging offers the advantage of grid independence, crucial during power outages or in remote locations. However, this method comes with significant drawbacks, such as slower charging speeds compared to using a Tesla Supercharger and environmental concerns associated with gasoline-powered generators.

Charging Time Comparisons

While generators ensure charging capability in a variety of settings, their efficiency significantly lags behind that of Tesla Superchargers. The convenience of portable charging must be weighed against the slower charging speeds and longer wait times.

Compatibility Assessment

The compatibility between the Honda EU2200i and Tesla’s charging system is a result of the inverter generator’s ability to produce clean AC power, which the Tesla can convert to DC for battery storage. This capability addresses the AC versus DC issue, making the generator’s AC output suitable for Tesla vehicles, albeit with limitations on charging speed and efficiency.

Impact on Carbon Reduction and Sustainability

Charging a Tesla with a gasoline-powered generator poses a contradiction to the vehicle’s environmental benefits. The Goal Zero Yeti 3000X solar generator offers a more sustainable solution, providing solar-powered charging that aligns with the green principles of EV ownership without the carbon emissions associated with traditional generators.

Conclusion – Charge Tesla With Generator

Charging a Tesla with an inverter generator like the Honda EU2200i is a practical solution under specific circumstances, offering a bridge between traditional power sources and the advanced technology of electric vehicles. However, the trade-offs in charging speed, convenience, and environmental impact highlight the importance of considering alternatives.

Solar-powered generators represent a promising step towards combining the flexibility of portable charging with the commitment to sustainability inherent in electric vehicle use. As the landscape of EV technology evolves, prioritizing solutions that offer a balance between innovation and environmental stewardship will be key to navigating the future of transportation.

Staff Writer
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