All manufacturers show their autonomy in the descriptions or specifications of each electric car model, which are usually between 300 and 500 km in many current cases, and ranges above that are already beginning to be promised. This depends largely on the development of batteries, and the ability to increase the density for each cell, to avoid raising the weight or size of this energy unit too much. But is that real autonomy?
The truth is that no In practice, it is seen that autonomy depends on many factors, and that this autonomy is not always achieved, especially when it comes to long-distance trips, where greater performance is demanded when traveling on highways at higher speeds. That is to say, precisely when autonomy becomes most important, is when we have the least autonomy...
Autonomy estimated by the manufacturer
La Autonomy is one of the most important aspects to consider when buying a plug-in electric car (CEV). Car manufacturers use various methods to calculate the range of their batteries, but they are not always comparable or reflective of practical world conditions, so in practice we are dealing with reality. To calculate the values ​​declared by the manufacturer, various calculation methods are usually used, such as:
- WLTP cycle: The World Harmonized Light Vehicle Test Procedure (WLTP) is an international standard used to measure fuel consumption and CO2 emissions of vehicles, including CEVs. The WLTP cycle simulates a variety of driving conditions, but some experts criticize its realism, given that they are carried out under controlled conditions. Additionally, not all manufacturers may be using this standard.
- EPA: The United States Environmental Protection Agency (EPA) uses its own test method to determine the autonomy of CEVs. The EPA cycle is shorter and less demanding than WLTP, which usually results in higher range values, but which you can trust even less, so WLTP is the more accurate of the two.
- Independent testing: Some independent organizations, such as Consumer Reports, conduct their own range tests to evaluate the performance of CEVs in real-world conditions. Therefore, it is better to read reviews or tests of this type to know the real autonomy of the model you want, and you will see how they do not correspond to those provided by the manufacturer, since that figure tends more to marketing than anything else...
Keep in mind that, even in the most real and precise simulations or tests, the autonomy figure may not be exact, and it depends on many conditions or factors, as I will show in the next section.
actual autonomy
As I have mentioned, battery autonomy does not always comply with the manufacturers' standards or measurement tests, in reality, in practice, the actual autonomy is different, and depends largely on:
- Engine efficiency: The efficiency of the electric motor is measured in percentage. An efficient electric motor converts more energy into motion, increasing range. This will vary from the quality of the motor and the materials used.
- Driving style: Speed, acceleration and use of elements that consume electrical energy during trips will also be included in the actual autonomy. For example, aggressive driving or higher speed driving can drain the battery sooner, even if the air conditioning or heating is turned on.
- Weather conditions: Extreme temperatures, both hot and cold, can reduce battery life. And this can also be related to the use of air conditioning. Furthermore, in extreme conditions of high temperatures, the battery can be damaged and reduce its useful life, while in extreme climates with low temperatures, the electric car could stop working, as we have seen with snow storms in some Nordic countries, with electric cars stopped while the combustion ones continued running.
- Other factors: of course it affects the capacity of the battery, the weight of the vehicle and the occupants or the load, the condition of the battery (with the charge and discharge cycles it loses some capacity), or the aerodynamics, the lower the Cx coefficient or resistance or drag, the lower, the more meters you can travel with the same load, as you do not have to supply more energy to the motors to move.
- Pavement: driving on terrain such as sand, loose gravel, snow, mud, or with greater friction, will cause the actual autonomy to decrease, while surfaces such as asphalt, cement, etc., will improve this problem.
That is, we find the following:
| Factor | Description | Impact on autonomy |
|---|---|---|
| Battery capacity (Ah or Wh) | Amount of stored energy | The greater the amount of energy available, the greater the autonomy. |
| Engine efficiency | Amount of energy converted into motion | Greater efficiency, greater autonomy. |
| Driving style | Speed, acceleration, use of accessories that consume electricity. | Efficient driving, and lower consumption use, greater autonomy. |
| Weather conditions | Room temperature. | With extreme temperatures, less autonomy. High temperatures can also damage the battery, and very low temperatures leave the car unable to run. |
| Vehicle design | Vehicle mass and aerodynamics. | Greater weight and greater drag or aerodynamic resistance, less autonomy. |
| Battery status | Useful life or charge/discharge cycles. | Decrease in capacity over time, especially after 8 years. |
How to reduce consumption and extend charge life
Finally, there are some tips that you can carry out so that the real autonomy is somewhat longer, and that happens through:
- Travel planning: If you are going to make long-distance trips, remember to plan the route in advance and locate charging points. Avoid areas/peak hours with traffic jams or heavy traffic to avoid spending too much time on the road.
- Driving: you can have a smooth drive, without sudden accelerations and braking, maintain a constant speed, use ECO mode when possible, let the car go when braking or reducing, instead of stomping on the brake to recover energy with the regenerative braking, try to use the air conditioning as little as possible, or maintain more moderate temperatures. Do not open the windows or sunroof, as this increases aerodynamic drag.
- Maintenance: It is also very important to keep the tire pressure at the recommended level, since underinflated tires will consume more. Perform regular car maintenance to check that everything is working properly. You should also keep the battery charged, preventing it from completely discharging or dropping below 40% when possible. Also, do not leave the vehicle plugged in for long periods of time.
- Reduce ballast- Avoids all unnecessary weight of the vehicle.