EV Charger Introduction

This article is an introduction to the different types and speeds of EV chargers as applicable to New Zealand. It will consider the different types of EVs and Chargers (EVSEs) available and relates the power to a domestic heater.  

For this we will consider 3 different EVs, with imported Nissan Leafs being most popular in New Zealand, The Renault Zoe with the best AC charger, but no Rapid Charger compatibility, and a Tesla Model S with a large battery. 

EVs for Comparison

Nissan LEAF	Renault Zoe	Tesla Model S
24kWh or 30kWh battery 15kW / 100km Range: 135km # in NZ 4245	41 kWh battery 15kW / 100km Range: 250km # in NZ 83	75kWh or 100 kWh battery 20kW / 100km Range: 400km to 500km # in NZ 260

Connectors & Chargers

For more information on connectors – please see our connectors article. 

Charger Types

Mode 2	Mode 3	Mode 4
AC Single Phase Plug into wall 8A, 1.8kW Max	AC Single or 3 Phase Hard wired Wall Mount 32A 7.2kW Single Phase 32A 22kW 3Phase	Rapid DC Floor Mount 50kW

What about Mode 1? Mode 1 is simply an extension cable and is only suitable for low capacity  E-bikes, scooters etc as there is no safety protection features included. 

See more information on charger modes in this article.

EVSE Mode Comparison

How Fast does an EV Charge?

The following factors determine the speed to charge an EV

• Battery size – Bigger takes longer
• Battery health and age
• Battery charge level
  • Cell balancing reduces charge rate
  • Generally takes longer to charge from 80% to 100%

• EV’s onboard AC charger
• EV’s onboard DC charger
• Electric Vehicle Supply Equipment (EVSE)’s Power Supply
  • Mode
  • Single or 3 Phase AC power
  • Load Sharing

See our article about for more information about charging speeds.

Plug in Chargers – Mode 2

Electric Heater 2300W 2.3kW on High 1300W 1.3kW on Low Run the heater for 1 hour on low = 1.3kWh.	Plug in Charger Max 8A, 1.8kW Charge an EV for 1 hour = 1.8kWh = 10km Range	Nissan LEAF 24kWh or 30 kWh battery 80% charge at 1.8kW 10 hours for 24kWh battery.

Wall Chargers – Mode 3 Single Phase

Our JuiceBox 40 is a Mode 2 single phase EVSE.

Electric Heater  3x 2.3kW on High Run 3 heaters on high for 1 hour = 7.2kWh.	AC Wall Charger Max 32A, 7.2kW Charge an EV for 1 hour = 7.2kWh = 45km Range

Wall Chargers – Mode 3 Three Phase

Our JuiceBox 32 is a Mode 2 Three Phase EVSE. (It also supports single phase installation if required). 

Electric Heater  9x 2.3kW on High Run 9 heaters on high for 1 hour = 22kWh.	AC Wall Charger Max 32A, 22kW Charge an EV for 1 hour = 22kWh = 140km Range

DC Rapid Chargers – Mode 4

Electric Heater 22x 2.3kW on High Run 22 heaters on high for 1 hour = 50kWh.	DC  Charger Max 50kW Charge an EV for 1 hour = 50kWh = 300km Range

Technical Considerations

Most homes have single phase power so a Mode 2 charger is suitable for charging one EV. If a home has more than one EV, load sharing will be required. 

Install with 3 phase power where available for future proofing. Users want bigger batteries for more range which will drive need for faster chargers.

Not just power

• WiFi / Network access for EVSEs (Network and cellular reception can be poor in carparks). There could be costs of network connections, or wiring LAN connections to EVSEs.
• If network goes down what happens? JuiceBoxes default to a safe operating current.
• If EVSE has RFID tokens – replace lost tokens, setup etc. How easy will this be for unit holders and managers?
• User requirements for cost effective quick charging.
• Compatibility between EVSE and EVs

Other Introductory Articles

• Charging a Nissan LEAF
• EV vs ICE Jargon
• Glossary
• EV Resources