Is it possible to charge an electric car with a generator?

The passage of Storm Kristin through Portugal left a trail of heavy rain, strong winds, flooding, and, in many areas, prolonged power outages (which, at the time of writing this article, are still affecting hundreds of homes). For those who rely on their car on a daily basis—whether for work, to support family members, or simply to get around—these situations raise a very concrete question among electric vehicle drivers: if the power goes out, is it possible to charge an electric car with a generator?

The short answer: yes, but with many limitations

From a technical point of view, it is possible. An electric car can start charging from any alternating current source that meets three essential requirements:

• Voltage at the correct level;

• Sufficient minimum power;

• Stability of the electrical current.

That is why there are reports of electric vehicles recognizing portable generators as an energy source and initiating charging.

The problem is everything that comes next!

Power outages expose the weaknesses of the solution.

During extreme weather events, such as Storm Kristin, many public charging stations become inoperative and even home chargers stop working. At first glance, a generator may seem like a logical emergency solution. However, most portable generators were not designed to power sensitive systems such as electric vehicle chargers.

In many cases, the available power is not even enough to initiate charging. When it is, the process is extremely slow, allowing only a few kilometers of range to be recovered per hour—insufficient for those who need to travel quickly.

Power quality is critical

Electric cars are particularly demanding when it comes to electricity quality. Voltage fluctuations, unstable frequency, or an imperfect electrical waveform cause the vehicle itself to interrupt or refuse charging, protecting its electronic systems.

For this reason, when this solution is attempted, only inverter generators (generators that produce direct current and convert it into alternating current), capable of delivering a stable waveform, achieve minimally consistent results. Even then, there are no guarantees.

Safety!

Another critical point concerns grounding. Many generators do not have proper grounding, which prevents charging or leads some users to resort to improvised adaptations. These solutions can be dangerous, increasing the risk of electric shock, damage to the charger, or to the vehicle itself.

In a storm context, with high humidity and waterlogged ground, as occurred during Storm Kristin, these risks become even more significant.

When might it make some sense?

Charging an electric car with a generator should only be considered as a last resort, in very specific scenarios:

• Prolonged power outages in isolated areas;

• An urgent need to recover enough range to reach a safe location or a functioning charging station;

• Use of a quality inverter generator with adequate power;

• Charging current limited to low values.

Even in these situations, it is an inefficient, costly, and environmentally contradictory solution, as it converts fossil fuel into electricity just to allow a few kilometers of travel.

Extreme events such as Storm Kristin show that electric mobility still depends heavily on the stability of the power grid. Charging an electric car with a generator is possible, but it is not a practical or recommended solution for regular use. It should be seen only as an emergency measure, used with caution and full awareness of the risks involved.

Whenever possible, alternatives such as operational public charging stations, charging at destinations where power has been restored, or backup solutions specifically designed for electric vehicles remain preferable.