Updated Jan 2024:
If you’re considering transitioning to a fully electric vehicle or plug-in hybrid, you’ll quickly find there are many different options for how and where to charge it.
Some scenarios, like plugging in at a public charging station, will take more time to ‘re-fuel’ than a petrol vehicle, but fast charging an EV isn’t critical in every situation. EV charging technology has its advantages too, especially when it comes to charging an EV at home where flexibility and convenience are major benefits.
In this article, we'll cover what you need to know about a range of different charging options, explain how they influence charging speeds, and review their overall impact on your EV charging time so you know what to expect when you plug in an electric car.
What impacts EV charging time?
There are three main factors that determine the amount of time it takes for your electric vehicle to charge. The charging speed of the EV charger you use, the maximum charging rate of your EV’s onboard charger, and your vehicle's total battery capacity / how much range you need to recover.
The different EV charging options to fill up your electric vehicle
Let’s start by reviewing the different EV charging options you can access in New Zealand.
DC charging systems
Also known as Mode 4, fast chargers, super chargers, or rapid charger, the terminology around DC charging technology can be a bit intimidating. We’ll outline the speed differences of these charging options below, but the important thing to remember is that DC charging provides the quickest charging method for EV drivers.
Due to their ability to recover a large amount of range when time is crucial, they are commonly used in public charging infrastructure and can be found via roadside charging stations to support EV’s on longer road trips.
AC charging systems
AC chargers, also known as Mode 3 or wall chargers, like the Evnex E-Series, are specially installed equipment designed for regular home charging or workplace charging. They balance ownership cost with a charging speed that can still refill an electric car’s battery overnight when your vehicle is stationary.
Portable car chargers on the other hand, or Mode 2, plug directly into a three pin household socket and produce the slowest charging speeds. While they are typically provided with an EV, portable chargers are generally not recommended for everyday use. They are best kept on hand as a backup charging method.
AC & DC charging rates
- DC chargers have a power rating that typically range from 25kW to 350kW. In New Zealand, most are 50kW with some 300kW appearing at key locations.
- Installed AC chargers range from 3.7kW to 22kW, with single phase 7.4kW being common in New Zealand.
Check out the charging speed grid below to see how these power ratings translate to estimated km of range recovered per hour of charging.
How your EV's onboard charger influences your charging time.
It is important to understand that during DC charging, energy is offered directly from a charging station to your vehicle's battery. On the contrary, AC charging requires that the electricity is converted from AC to DC before being stored in your EV's battery. Therefore, when charging from an external AC charger, your charging speed may be constrained by your car’s onboard charger, even though the AC charger can offer faster charging speeds.
As an example, let’s say you have a 22kW AC home charger installed, but your EV can only achieve a maximum charge rate of 6.6kW via its onboard charger. While the AC charger is offering a much higher rate of charge, it is constrained by how fast your vehicle can convert that AC power to DC.
In this situation the highest charging speed your vehicle could achieve using an AC charger would be 6.6kW. Although it may seem unnecessary to install an EV charger with a higher capacity than your vehicle supports, it’s worth considering the upgrade for potentially gains in safety features, smart charging options, and future-proofing purposes.
AC chargers require the vehicle's internal on-board charger to convert from AC to DC. DC charging stations feed DC directly into the battery.
When planning on buying a home charger for your electric car, it’s helpful to review the maximum onboard AC charging speed of your vehicle. You can safely install an EV charger with a higher power rating than your car supports, but you won’t access the full potential of the charger's speed (unless you upgrade your EV in the future).
This also applies to DC charging, as there will also be a maximum DC charging rate set by the vehicle manufacturer.
Your EV’s battery pack and how much range you need to recover
How long it takes to charge your EV will ultimately come down to how much range you need to recover.
While stats often show how fast it takes to charge an EV from 0% to 100%, you’ll likely be completing shorter charging sessions more frequently, as home-charging offers more flexibility and convenience than going out to re-fuel in large amounts .
The average daily commute in NZ is around 25-35km a day and 32-40km in AUS. Using an 7.4kW AC charger, you can recover this range in as little as one hour of charging at home each day when your EV is parked.
The table below provides a guide to charging times with estimated km / hour of charging. The larger the EV's battery size and the slower the charger, the longer it will take to reach a full charge.
* The information in the above table is approximate and real-world charging speeds will vary depending on an electric vehicle's battery size. This table is based on a vehicle with a 64kWh battery. Only some EVs will accept higher delivery speeds from ultra-rapid chargers.
You may note that for DC chargers, we refer to the charging time as the time to reach 80%. This is because the charging rate usually decreases significantly towards the end of the charge. If you're using a DC charger during a long trip, generally you'll only charge to around 80%, as you'll see diminishing returns as you approach 100%. It's generally considered good etiquette to stop charging once you reach 80% capacity as well if there are other drivers waiting to use the public charger.
AC - Alternating Current; this is the type of electricity you use in your home.
DC - Direct Current; this is the type of electricity used when charging or consuming energy from a battery.
kW - Kilowatt; a unit of measurement for electrical power. For example, a Generation 2 Nissan Leaf can produce a maximum of around 80kW of power.
kWh - Kilowatt-hour; a unit of electrical energy. If an appliance uses 2kW of power for an hour, then it is said to have used ‘2kWh’ of electricity. Typical electric car batteries range from 24kWh to 100kWh.
Charging station - Typically referring to public chargers on a network.
Charge point - Can refer to any fixed EV charger but is often used when describing public chargers.