If you’re an entrepreneur looking to fit EV charging points, then the 120kW EV charger is the one to watch for its balance of speed and cost. Everyone’s wondering: how long really does it take to charge a car? While the quick answer is 20 to 30 minutes to charge from 20% to 80% state of charge (SoC), the entire story is actually somewhat more complicated. This guide breaks down the 120kW EV charger charging time, explaining the key parameters that determine how quickly an automobile can be moving.
The Short Answer: The 20-30 Minute “Sweet Spot”
For the typical modern electric car with a battery pack size 60-100 kWh, a 120kW EV charging point can deliver a high-charge in a relatively brief space of time. The typical session, low charge to 80%, lasts between 20 and 30 minutes. This duration is ideal for business premises like shopping centers and highway service stops as it correlates to a customer’s natural stay time.
Why Isn’t It Always 120kW? The Four Big Limiting Factors
The “120kW” on the sticker is a theoretical maximum. The actual charging power, and therefore time, is determined by the weakest link in the chain. The four factors that can limit the output of a 120kW EV charger are as follows:
- The Car’s Battery & BMS: The car is in control. Its battery voltage (say 400V or 800V) and its Battery Management System (BMS) dictate how much current it will take. When filling the battery (especially above 80%), the BMS reduces power to the battery to save the battery and decreases the charging.
- The Current Rating of the Cable: Regular cables are usually rated at 200A. With the power formula (Power = Voltage × Current), a 400V car on a 200A cable is limited to ~80kW, not the full 120kW.
- The Nameplate Power of the Dispenser: The physical charging point itself also has a power rating maximum.
- Power Allocation of the Site: A central power cabinet provides power to several dispensers. When numerous cars are being charged simultaneously, the available power for every 120kW EV charger may be dropped in order to prevent the overloading of the system.
The last charge power is the smallest of the four.
Calculating Charging Time: An Example from the Real World
If you have the actual average power, to make an estimate of the time, use the following formula:
Charging Time (hours) = Battery Capacity (kWh) ÷ Actual Average Power (kW)
Let’s assume you have an EV with an 80 kWh battery that needs to go from 20% to 80% (48 kWh of energy needed) on a 120kW EV charging station.
- Scenario A: Best Case (800V Vehicle)
Voltage: 800V, Current: 200A
Actual Power: 800V × 200A = 160 kW (But capped at 120 kW by charger)
Time: 48 kWh ÷ 120 kW = 0.4 hours (≈24 minutes)
- Scenario B: Real-World Blend (400V Vehicle)
Voltage: 400V, Current: 200A
Actual Power: 400V × 200A = 80 kW (Limited by lower car voltage)
Time: 48 kWh ÷ 80 kW = 0.6 hours (≈36 minutes)
- Scenario C: Tapering Effect (Average Power)
The charge starts off at 120kW but tapers off as the battery fills up, providing an average of 90 kW.
Time: 48 kWh ÷ 90 kW ≈ 0.53 hours (≈32 minutes)
This shows why the 20-30 minute forecast is a reasonable estimate. The time is actually governed by which limiting factor.
Conclusion: The Perfect Commercial Solution
The 120kW EV charger provides an amazing balance. It provides fast, convenient charge that will meet drivers’ needs without the exorbitant infrastructure costs of higher power alternatives. With knowledge of the charging time being dependent on car and circumstances, you can handle customer expectations in the right way. For organizations seeking the assurance of return on investment, the 120kW EV charger remains the smart, strategic option for public and commercial charge installations.
Ready to take advantage of efficient 120kW EV charging systems? Contact us for a professional assessment.