EV Charging Speed and Time Quiz

Question 1

A 75 kWh EV is charged from 20% to 80% on a 7.2 kW Level 2 station. Approximately how long?

Accepted Answer

6.25 hours

Answer

4 hours

Answer

10 hours

Answer

12 hours

Question 2

Why does charging slow down above ~80% SOC on a DC fast charger?

Accepted Answer

The battery management system reduces power to protect the cells

Answer

The station hits its kW limit

Answer

Higher voltages cause overheating in the cable

Answer

It does not — that's a marketing claim

Question 3

A car has a 7.2 kW onboard AC charger. It is plugged into an 11 kW Level 2 station. What rate does it draw?

Accepted Answer

7.2 kW (vehicle max)

Answer

11 kW (station max)

Answer

9.1 kW (the average)

Answer

18.2 kW (sum)

Question 4

For DC fast charging, what limits the peak charging rate?

Accepted Answer

The station's max output, the vehicle's peak DC rate, and the current SOC/temperature — whichever is lowest

Answer

The onboard AC charger

Answer

The cable thickness only

Answer

The driver's payment method

Question 5

A driver pulls up to a 150 kW DC fast charger but only sees 50 kW on the dashboard. Most likely cause?

Accepted Answer

Their vehicle's peak DC rate is around 50 kW

Answer

The station is broken

Answer

The connector is wrong

Answer

They have not paid

Question 6

How does cold weather affect EV charging speed?

Accepted Answer

Slower, especially below freezing — until the battery warms up

Answer

No effect — temperature does not matter

Answer

Faster charging in cold weather

Answer

Faster initially, then slower

Question 7

Which is the practical road-trip rule?

Accepted Answer

Charge to 80% and continue — the last 20% is the slowest

Answer

Always charge to 100% before continuing

Answer

Never use DC fast charging

Answer

Only charge between 50% and 70%

Why charging speed is confusing