Understanding how electric vehicles charge
Electric Vehicles (EVs) are becoming a more familiar sight on Newfoundland and Labrador roads, but for many people, one question still remains: how exactly do they charge?
At College of the North Atlantic (CNA), students in the Automotive Service Technician program will soon be learning the answer.
Inside a classroom at Prince Philip Drive campus in St. John’s, CNA instructor Dennis Terry is helping prepare the next generation of automotive technicians to understand the technology driving the future of transportation – and why charging an EV is more complex than simply plugging it into a wall outlet.
Changes to program plans in automotive entry-level programs and apprenticeship training will integrate electric vehicle instruction into CNA’s automotive programming. The shift marks an important step in preparing the next generation of technicians for a rapidly changing industry and reflects the work already happening behind the scenes as the college continues developing programming focused on electric vehicle maintenance, service and safety.
“People hear terms like kilowatts, charging levels, or fast charging, and it can sound intimidating at first,” Terry said. “But once you break it down, you start to realize there’s a system behind it and understanding that system is becoming more important every year.”
Terry teaches advanced automotive courses, including Level 4 programming that focuses on EV technology and charging systems. As more manufacturers shift toward electric vehicles, understanding how batteries charge and what affects charging time, is quickly becoming an essential skill for technicians entering industry.
At the centre of every EV is the high-voltage lithium-ion battery. Much like a fuel tank in a traditional gasoline-powered vehicle, the battery stores energy that powers the vehicle. But unlike filling up at a gas station, charging an EV depends on several factors working together.
“One of the biggest misconceptions is that every EV charges the same way,” Terry explained. “The reality is that charging time can vary depending on the size of the battery, the type of charging station being used, the vehicle’s onboard charging system, and even the outside temperature.”
To help future technicians understand the concept, Terry begins with two key measurements: kilowatts (kW) and kilowatt-hours (kWh). Kilowatts measure the rate at which energy is used or supplied, while kilowatt-hours measure the total amount of energy stored in the battery.
That battery capacity also determines how far an EV can travel.
According to Terry, many electric vehicles can travel approximately four to six kilometres for every kilowatt-hour of stored energy, depending on factors such as driving habits, road conditions and vehicle design.
“Efficiency is a big part of the conversation around EVs,” he said. “But before you can understand efficiency, you first need to understand how the battery is being charged and managed.”
Future students at CNA will learn about three primary charging levels currently used across North America.
Level 1 charging uses a standard 120-volt outlet and is the slowest form of charging, typically adding only a small amount of driving range per hour. Level 2 charging uses a 240-volt system, like a household dryer outlet, and can charge a vehicle significantly faster. Level 3 charging, commonly known as Direct Current Fast Charging, delivers direct current straight to the battery at much higher power levels, dramatically reducing charging time.
Terry often compares fast charging to pouring water into a glass.
“At first you can pour quickly, but as the glass gets full, you need to slow down,” he explained. “Fast charging works the same way. Once the battery reaches around 80 per cent, the charging rate slows to protect the battery from overheating.”
Another important lesson for future technicians will be understanding that the charging station itself is not technically the charger.
In Level 1 and Level 2 charging, the vehicle contains an onboard charger that converts incoming AC power into the DC power needed by the high-voltage battery. The vehicle’s onboard charger also determines how much power the vehicle can accept.
“That’s where the term acceptance rate comes in,” Terry said. “Even if a charging station can provide a large amount of power, the vehicle can only accept what its onboard charging system is designed to handle.”
Future students will work through real-world charging scenarios to calculate how long it would take different vehicles to charge under different conditions. Those calculations will help them understand how battery size, charging output and onboard charging limitations all work together.
Temperature also plays a major role.
Cold weather can slow charging times because the electrolyte inside the battery thickens, reducing the movement of ions within the battery. Excessive heat can also damage battery health over time. According to Terry, high-voltage batteries perform best between 15°C and 35°C.
“In Newfoundland and Labrador, temperature is something EV owners absolutely need to think about,” Terry said. “Understanding how climate affects battery performance is part of preparing students for real-world service situations here at home.”
For Terry, one of the most exciting parts of teaching EV technology is how quickly the field continues to evolve.
“This industry changes constantly,” he said. “What students are learning today is preparing them for vehicles and systems that are still evolving. That’s what makes it exciting.”
As electric vehicle adoption continues to grow across Canada, Terry believes education will play a major role in helping both technicians and drivers feel more confident with the technology.
“The more people understand how EVs work, the less intimidating they become,” he said. “That knowledge is what helps build confidence for the future.”
Sidebar: The Future of Electric Vehicles in Atlantic Canada
Electric vehicle infrastructure continues to expand across Atlantic Canada, with more public charging stations appearing in communities, along highways and near businesses.
As charging networks grow, the technology behind electric vehicles is also evolving rapidly. Newer fast-charging stations are capable of delivering significantly higher charging speeds, while manufacturers continue to improve battery range and efficiency.
At CNA, future students will be learning about these changes in real time.
“This is an ever-changing field with constantly updated topics,” said Dennis Terry. “The technology keeps moving forward, and the industry needs technicians who understand how these systems work.”
With the automotive industry steadily shifting toward electrification, training programs focused on EV systems, charging technology and battery diagnostics will become increasingly important for the future workforce.
