03.7 Electric vehicle charging
EVs are charged at home or at public charging stations
EV drivers primarily charge up at home, usually overnight. A recent social media poll found of 362 EV drivers, three quarters of them charged at home 95% of the time.
Public electric vehicle charging infrastructure is primarily used for convenience or long distance travel, so are often located in carparks & shopping centres. Fast charging is also being installed at petrol stations & highway rest stops.
As of June 2021, there were 3,000 public EV charging units nationally, with millions of dollars of government & private sector funding invested in accelerating roll out.
You can locate your nearest public EV charging units using a search app like Plugshare or A Better Route Planner.
Three levels of EV charging
Level 1 - AC single or three phase powerpoint
Slowest rate of charge, approximately 10-25kms of range per hour of charging.
Using an 'electric vehicle supply equipment' (EVSE) cable, an electric vehicle can be connected to a normal household powerpoint. Usually 10 to 15 amps.
Power is supplied by the EVSE cable to the vehicle's onboard inverter, which converts AC grid power to DC power, the type stored by the traction battery.
Level 2 - fixed AC charging unit, 7kW or 22kW
Faster rate of charge, approximately 30-40kms of range per hour of charging.
A connected wall-mounted charging alternating current (AC) unit at 7kW (single phase) or 22kW (three phase). Installed in homes, apartment buildings, shopping centres & other public spaces. May be installed close to solar panels & domestic battery energy storage systems.
Level 2 chargers require 40amps per phase x the number of ports (single or dual port units are both available).
Power is supplied by the unit to the vehicle's onboard inverter, which converts AC grid power to DC power, the type stored by the traction battery.
Level 3 - DC charging unit, 25kW to 350kW
Fastest rate of charge, upwards of 150kms of range per hour of charging.
Known as rapid or ultra rapid, DC units are large, floor mounted chargers popular in commercial locations or roadside services. May be installed near large scale solar carports & battery energy storage systems.
Level 3 chargers require 50 to 500amps per phase x the number of ports (single or dual port units are available).
AC grid power is supplied to the DC unit, where it is converted to DC power before being supplied directly to the vehicle traction battery. This speeds up the charging process.
Regenerative braking also delivers charge to an EV battery
All electric vehicles use regenerative braking, which allows the vehicle to harvest kinetic energy while braking & supply it to the traction battery as useable power.
While slowing down, the reverse force on the electric motor magnets converts rotational energy into electrical energy. This transfer of energy from the wheels to electric motor slows the vehicle down, in some cases, quite rapidly, which is why EVs are sometimes referred to as 'one pedal driving'.
Regenerative braking doesn't supply as much power to the traction battery as an AC or DC charging unit, however it is enough that emergency responders, roadside assistance & tow truck drivers should be mindful of moving an EV to avoid a supply of power to a damaged battery