The Safety Mechanisms of Electric Vehicles During Charging
Are you concerned about accidentally leaving your electric car on while it's charging?
Understanding Your Car's Charging Process
Electric vehicles, such as the Kia Soul EV or Nissan Leaf, are designed with specific mechanisms to ensure safe and efficient charging.
For instance, in the case of the Kia Soul EV, it is essential to turn the car off to open the charging door, and the car must be turned off to remove the charging cable. However, once the charging process has started, you can operate various accessories in the car, such as the stereo, air conditioner/ heating system, and phones. It's clear that the designers of these vehicles have carefully considered the safety aspects of charging.
Charging Currents and Battery Protection
When charging an electric vehicle, the battery is receiving a large amount of energy, which is why it is crucial not to drive the car while it is charging. The powerful 200-300 horsepower motor would deplete the battery much faster than a wall outlet can charge it.
Once the car is plugged in, it will not allow the drive motor to operate, but it will still provide power to the little accessories such as the radio, air conditioning, and power windows. This feature is convenient for public fast-chargers where you can watch TV or listen to your favorite radio station.
The built-in charger in the Nissan Leaf will stop charging once the battery reaches 100% and the EVSE (Electric Vehicle Supply Equipment) will automatically turn off. At a level 2 EVSE, the main battery and the 12V battery are charged in parallel provided the EVSE remains on. If the car is in any mode other than off, the 12V battery will be charged from the main battery.
Fail-Safe Mechanisms for Battery Protection
The Nissan Leaf has several fail-safe mechanisms to prevent the 12V battery from running down. When in auxiliary mode (with just the radio on), the car will turn itself off after a set timer. In drive mode, the car will not turn off by itself, which is important for safety reasons. The A/C on mode might not turn off within minutes, but the 12V battery will still be protected.
For both vehicles, if the car is left for months without charging, the main and 12V batteries may run down over time. However, if the car is plugged in at a level 2 EVSE, it will charge to full and turn off, potentially depleting the 12V battery. A faulty battery could result in the need to charge the 12V battery separately.
Experimenting with Charger While Car is On
Some users might wonder what happens if you leave the car on while charging. In one experiment, the car was at 85% and left charging for 3 hours. The battery did not drop below 97%, indicating that if the air conditioning was turned off, the car can continue to charge for some time without depleting the battery significantly.
Conclusion
In summary, electric cars are designed with various fail-safes to prevent the main and 12V batteries from depleting while charging. Leaving the car on while charging may pose risks, but the current mechanisms in place are designed to minimize these risks. Always ensure to follow the manufacturer's guidelines to ensure the safe and efficient operation of your electric vehicle.