What is a Level 3 charging station?

Level 3 Charging Stations are the fastest on the market today. Able to deliver between 50 kW and 400 kW power, charging for one hour with a Level 3 charging station can add between 173 miles (278 km) and 298 miles (480 km) range, depending on the power output. 

For more details on the differences between the three levels of EV charging before we get into Level 3 charging, check out this blog explaining EV charging levels.
When it comes down to it, Level 3 EV charging is the fastest of the three currently available levels for EV drivers. Depending on the power output, a Level 3 Charger can charge an EV in minutes compared to the hours it takes for both Level 1 and 2 chargers.

For instance, at the highest power output, a Level 3 charger can charge an EV to 80 percent anywhere between 15 and 60 minutes. To find out more about how fast Level 3 charging stations are and the different factors that affect charging speed, we wrote another article exploring exactly that. 

Thanks to the fast speeds it unlocks, Level 3 charging is perfect for short stops along highways, inner-city charging on the go, commercial businesses like gas stations, and business fleets like taxis or delivery vehicles. 

How do Level 3 charging stations work?

To understand how Level 3 charging works, it’s important to understand the different types of electrical current. 

The power from the grid is always alternating current (AC)
EV batteries only accept direct current (DC) 
These two factors mean that at some stage, the current must be converted from AC from the grid to DC to be stored in an EV’s battery.

With Level 1 and Level 2 charging, the conversion (from AC to DC) happens in the vehicle itself via an onboard charger. With Level 3 charging, the transformation happens before the power reaches the vehicle, bypassing the slower onboard charger and feeding directly into the vehicle’s battery. Whilst Level 3 chargers come in many shapes and sizes, they all have one thing in common: the conversion happens outside the vehicle.

And as a result of the current already being converted by the time it reaches the vehicle, Level 3 charging stations can deliver power at higher speeds and are significantly faster than either Level 1 or Level 2 charging.

How much does it cost to charge an EV with Level 3 charging?

Generally speaking, Level 3 charging will always be more expensive than Level 1, and Level 2 charging, and at the time of writing this article the average price for a full Level 3 charging session lies somewhere between $25 and $50.

When you opt for Level 3 charging, you’re partly paying for the convenience of charging your electric car extra fast. You’re also paying for the investment by the charge point operator in the infrastructure, which is usually significantly higher than Level 1 and 2 charging.

Designing Level 3 DC Fast Charging Stations

Level 3 DC fast chargers bypass the Onboard Charger (OBC) of the Electric Vehicle (EV) and directly charge the battery via the EV Battery Management System (BMS). Bypassing the OBC enables significantly higher charge rates, with charger output power ranging from 50 to 350 kW. Common output voltages are 400–800V, with newer EVs trending towards 800V batteries. Since Level 3 (L3) DC fast chargers must convert three-phase Alternating Current (AC) input voltage to DC, they include an AC-DC Power Factor Correction (PFC) front-end with an isolated DC-DC converter to interface the PFC output to the EV’s battery. Multiple power modules are often paralleled to achieve higher output power. The main benefit of L3 DC fast chargers is significantly reduced charge time with charge rates ranging from three to 20 miles per minute of charging.

Our digital power solutions and SiC MOSFETs and diodes enable designs that offer higher system efficiency and integration, high power density, advanced control loops and increased flexibility in various power topologies that are optimized for DC fast charger applications. In addition, we offer a wide selection of 8-, 16- and 32-bit microcontroller (MCU), analog, power management, wireless and wired connectivity, energy metering, memory, security and Human-Machine Interface (HMI) solutions to complete any L3 DC fast charging design.