How Long Does It Take to Charge an Electric Car at a Public Charging Station?

Air pollution is a serious issue faced by major cities worldwide, including in Indonesia. Emissions from fossil fuel-powered vehicles are one of the biggest contributors to air pollution, which negatively affects both human health and the environment. As part of efforts to reduce this impact, electric cars are increasingly seen as an effective solution. However, one common question people have is: how long does it take to charge an electric car at a public charging station?

Public Electric Vehicle Charging Stations (SPKLU) are located in various strategic spots, making it easier for electric car users to recharge their vehicles while on the go. To find out how long it takes to charge an electric car, here’s a detailed breakdown.

Types of Public Electric Vehicle Charging Stations

In Indonesia, SPKLUs are becoming more common in public areas such as shopping malls, train stations, and highway rest stops. Broadly speaking, these charging stations are categorized based on how fast they can charge a vehicle:

1. Fast Charging Stations (DC Fast Charging)

This is the quickest charging option, often used to charge a car battery up to 80% in a relatively short amount of time. DC fast charging stations typically offer a power output of 50 kW or higher, with some stations around the world capable of reaching 150 kW or even 350 kW.

2. Medium Charging Stations (AC Charging)

These stations use alternating current (AC), making them slower than DC fast chargers. The power output at these stations typically ranges between 7 kW and 22 kW. While slower, they are still popular due to being more affordable and commonly installed in public spaces and residential areas.

3. Slow Charging (Home Charging)

Home charging is the slowest method, as it usually uses a standard electrical socket or a wallbox with power ranging from 2.3 kW to 7 kW. Fully charging a car can take several hours or even overnight. However, it’s the most convenient option for home use, allowing you to charge the car when it’s not in use.

Steps of Electric Car Charging

Charging an electric car generally involves several stages, from connecting the charger to the car until the battery is fully charged. Here’s a step-by-step explanation of the process:

1. Connection

• Plugging In: The user connects the charging plug to the car’s charging port.
• Authentication: The car and the charging station communicate to ensure compatibility and safety before starting the charging process.

2. Pre-Conditioning

• Battery Cooling or Heating: The Battery Management System (BMS) adjusts the battery’s temperature to an optimal level for charging. If the battery is too cold, it will be warmed up first, and if it’s too hot, it will be cooled down.
• Safety Check: The system checks the battery, cooling system, and other components to ensure everything is in good condition before charging begins.

3.Bulk Charging

• High Current: At this stage, a high current is delivered to the battery, allowing it to charge quickly.
• Voltage Limit: As the battery’s voltage reaches a certain threshold, the current automatically decreases.

4. Constant Current Charging

• Constant Current: The charging current is maintained at a constant level.
• Battery Protection: This stage is designed to protect the battery from overcharging.

5. Constant Voltage Charging

• Constant Voltage: The voltage is held steady while the current gradually decreases as the battery nears full capacity.
• Final Charging: This is the last phase of the charging process, where the battery reaches nearly full capacity.

6. Trickle Charging

• Individual Cell Charging: In some systems, each cell within the battery is charged individually to ensure voltage balance.
• Optimization: This stage aims to optimize battery performance and prolong its lifespan.

7. Charging Complete

• Disconnecting: Once the battery is fully charged or reaches the desired level, the charging process automatically stops.
• Notification: The user will receive a notification, either through an app or on the charging station’s display, indicating that the process is complete.

Factors Affecting Charging Time

Several factors can influence how long it takes to charge an electric car at a public charging station:

1. Charging Station Power Output

The time needed to charge depends on the power available at the station. DC fast chargers will recharge a vehicle much quicker than AC chargers or home setups.

2. Battery Capacity

Electric vehicles have varying battery capacities, typically measured in kWh (kilowatt-hours). Larger batteries will take longer to charge, even with a fast charger.

3. Battery Charge Level

How long it takes to charge also depends on the battery’s state at the start. If the battery is nearly empty, it will take longer to charge than if it is partially full.

4. Charging Efficiency

Charging isn’t always 100% efficient, as some energy is lost during the process, especially in extreme temperatures (too hot or too cold).

5. Ambient Temperature

Environmental temperature can also affect charging time. In very hot or cold conditions, electric car batteries may take longer to charge as the system works to maintain optimal temperatures.

6. Charger Type

The type of charger used plays a major role in charging speed. For example, a 150 kW DC fast charger will be significantly faster than a 7 kW AC charger.

Average Charging Times

Charging times for electric cars at public stations vary, but here are the typical averages based on the type of charger used:

1. Fast Charging (DC Fast Charging)

• A 50 kW fast charger can typically charge 80% of the battery in 30–60 minutes, depending on the car’s battery capacity.
• Higher-powered chargers (e.g., 150 kW) can charge up to 80% in just 15–30 minutes.

2. Medium Charging (AC Charging)

• Charging at stations with 7 kW to 22 kW output can take 4–8 hours for a full charge, depending on the battery capacity.

3. Slow Charging (Home Charging)

• Using a standard electrical outlet with a power of around 2.3 kW can take 10–20 hours to fully charge a vehicle.
• If using a 7 kW wallbox, charging time can be reduced to around 8 hours.

In conclusion, charging times for electric cars at public stations vary depending on the type of charger and the station’s power output. Fast charging with DC fast chargers can fill up to 80% of the battery in 30–60 minutes, while AC charging or home charging takes longer. Although the charging process may take more time than refueling a conventional car, the growing infrastructure of public charging stations ensures that you won’t run out of power during your journey.