Using the Public Charging Network

AC = alternating current, meaning, that the current moves in a waveform in a positive and negative direction. AC is typical for the powerlines and typically used in houses.

AC Charging means using an onboard charger, that is, an AC/DC converter onboard the electric car.

It is recommended by the NZTA that AC charging stations provide a Type 2 socket; the driver will be expected to provide their own supply cable that is compatible with their vehicle inlet.

Type 1 EVs can use AC commercial public charging stations so it’s a great idea to carry a Type 2 to Type 1 lead. Make sure that your rental comes with one for your holiday.

Two different AC power supply systems: Single Phase and 3-Phase.

In a single-phase connection, the flow of electricity is through a single conductor. A three-phase connection, on the other hand, consists of three separate conductors that are needed for transmitting electricity. In a single-phase power supply system, the voltage may reach up to 230 Volts.

Single Phase

• Most domestic supply from the grid to a household is 63 Amps per phase.
• Most domestic houses have 63 Amps.
• 2 wires wires called Phase and Neutral.

3 Phase 

• Supply from the grid is 63 Amps per phase.
• Three phase x 63 Amps = more power available at the address.
• Businesses and high demand households may have three phase to ensure that appliances can draw the required amps to function.
  • generators
  • industrial cleaning equipment
  • motorised equipment
  • heating and cooling
  • stoves and cooking equipment
• 3 wires (four wires if neutral wire is included).

If you aren’t sure, there are ways to check which phase you have:

• Check your fuse box and look for a black rectangular fuse — single phase has one and three phase has (you guessed it) three.

• Single phase units generally have one main switch while three phase have three.

DC = direct current, meaning that the current only moves in one direction. DC current is used for power transmission over great distances because it leads to less inductive losses.

DC Charging indicates using an offboard charger, that is, a charger located at the charging station, and not in the vehicle.

DC stations in New Zealand have a tethered charging cable. The NZTA recommends that DC charging stations provide tethered cables with both the CHAdeMo DC and DC CCS Type 2 (a sort of multi fit port) connector type. 

You won’t be able to get a fast charge at a DC public charging station if your car doesn’t have the matching DC charging port/inlet.

• You select the compatible supply cable and connector from the charging station and connect this to the electric vehicle inlet.
• The driver may then need to activate the power supply by using a start button on the charging station, radio-frequency identification (RFID) tag, swipe card, smart phone app or other device.
• Charging will start once access has been accepted and communication between the vehicle and the charger is established.

Does DC charge faster than AC?

Yes DC power is much faster than an AC charging station as there is less resistance for the current of electricity. However, the disadvantage of DC is that it is much more expensive to install than an AC charging station.

The rate a DC public charger will charge your car depends on the capacity of your onboard charger.

Factors affecting the rate of charge

The amount of time needed to completely charge an electric vehicle depends on several factors, including:

• battery capacity
• ambient temperature
• utility/grid constraints limiting the current available to the charging station
• temperature of the charging station
• charging type
• the vehicle’s battery management system (BMS)
• the capability of the on-board charger
• the amperage of the charging station

The amount of charge already in the battery also affects the speed at which a battery can recharge – the closer it is to empty, the faster the electricity can flow.

When a battery is charged to 80 percent the charging rate typically starts to taper off. Therefore, if a driver is paying by the minute at a fast charge station, it can become costly to charge over 80 percent and they may not wish to completely fill up.

Can I get DC ‘fast’ charging at home?

The short answer is no. A DC fast charger is designed for industrial and commercial settings. This is mostly due to the power requirements and expenses associated with a Level 3 charger.

The choice is yours:

AC public chargers will charge your Type 1 EV at the same speed you might get at home. Nissan Leafs, for example can only charge at 3.6kWh when using an AC supply. You’ll need a Type 2 to Type 1 Lead. You’ll get about 20 km of range per hour of charging.

DC public chargers are fast, and you may have to pay.

A Nissan Leaf can only do “faster charges” on DC using the CHAdeMO connector type. When you arrive at a DC Public Charging Station the tethered cable supplied will have a CHAdeMO handle which connects to your car.

CHAdeMO = The Japanese use this plug type for their fast charging network in Japan so EV’s imported from Japan come with this charging port as well. For example Nissan e-NV200, 2017 Mitsubishi Outlander, Nissan Leaf (Type 1).

Teslas can charge at Tesla-only DC charging stations (using a tethered cable with Tesla-specific plug), DC stations offering a Type 2 tethered charging cable, or at AC charging stations/wall chargers using your own Type 2 to Type 2 lead.

Make sure you keep a Type 2 to Type 2 charging lead in the car so that you have as many options as possible for achieving a charge. Accessing a fast or super-charge will become easier over time but currently these charging stations aren’t as widely available.