With more & more people purchasing and driving EVs, one of the biggest points of concern for potential EV buyers is how long it takes to charge. Most EV users charge at home overnight and for others, there are many places like offices, malls and restaurants to recharge. But to people who are used to waiting 5 minutes to fuel up a tank of gas, it seems like a long time to wait.
Currently, there are 3 levels of charging:
Level 1 AC charging has a nominal supply voltage of 120 V and a current up to 20 A. They are primarily used in residential settings, which use an onboard single-phase charger and have a power output of up to 2.4 kW. It is a plug-in technology and does not require any installation and hence is less expensive. The charging time is long, about 8 to 12 hours.
Level 2 AC charging has a nominal voltage of 240 V and a current up to 80 A. It uses an onboard charger and has a maximum power output of 19.2 kW. It requires installation work and hence is expensive as compared to level 1 AC charging. It is commonly installed in public parking areas, offices, malls, etc.
Level 3 charging, also known as DC fast charging, has an off-board 3-phase charger that supplies the DC power directly to the battery bypassing the onboard charger. Most DC fast chargers on the market charge at rates of 25-50 kW. Currently available DC fast chargers require inputs of 480 V & 100 A. New generations of DC fast chargers can produce 150-350 kW of power. Not every EV model is capable of DC fast charging. DC fast chargers have multiple standards for connectors (namely CHAdeMO, CCS, Tesla) whereas there is only one common standard for Level 1 & 2 (SAE J1772). DC fast charging can charge an electric car’s battery up to 80% of its capacity in 30-60 minutes.
While Level 3 is the fastest way to charge an EV, it is also the costliest.
The reason DC fast chargers are so expensive is that EV Fast-Charging Stations are one of the leading models of technology. Equipment for fast chargers is expensive. The wiring & software needed for Level 3 charging is very advanced. They require more space and very complex spare parts to facilitate processes such as active cooling. So companies setting up the stations charge more in order to make their money back. The price will go down with time as parts for the charger become less expensive.
Level 3 chargers are subject to high warranty & maintenance costs. Maintenance & warranty/insurance are typically more expensive for faster chargers as the components are under greater physical strain and at higher risk of damage.
The cost of power from a fast-charging station will be higher than that from a Level 1 or 2 unit unless the companies/owners of the fast-charging stations can find ways to increase utilization and maintain those high utilization rates.
Most EV charging networks offer discounted charging if you join a monthly or yearly subscription plan.
DC fast charging uses multiple connector configurations. Most models coming from Asian automakers use a CHAdeMO connector (Nissan Leaf, Kia Soul EV), while German and American EVs use the SAE CCS (BMW i3, Chevrolet Bolt EV), with many Level 3 chargers supporting both types. Tesla uses a proprietary connector to access its Supercharger network, which is limited to its own vehicles.
Charging rates are based on a per minute or per kWh basis depending on the country, company, etc.
DC chargers require significant investment. The hardware alone costs between $50,000 to $100,000, although costs are likely to fall significantly, about 40 per cent, over the next 10 years. Installation can more than double the cost, depending on the size and layout of the station. DC chargers also require high-powered grid connections.
Companies charge a premium based on location & speed of charging.
DC fast charging allows EVs to act more like conventional cars, with shorter ‘refill’ times. It provides a quick & efficient replenishment when needed but it costs a few extra dollars (or rupees in our case). This price is comparatively much lower than a full tank of petrol/diesel.
Fast chargers may become cheaper as the charging equipment become more affordable in the future courtesy of increased usage & economies of scale.