It can be daunting to understand electric cars and the terminology that accompanies them; especially when it comes to different EV charging technology. In this article, we'll cover what you need to know about a range of different electric car charging options, explain how they influence charging speed, and review their overall impact on your charging time.
There are three factors that determine how fast your electric vehicle will charge, firstly the speed of an EV charger, the maximum supported charging speed of the EV itself, and the vehicle's battery capacity.
The different types of chargers for electric cars:
DC Car Chargers
Also known as Mode 4 or rapid charger, DC chargers provide a faster charging experience for EV owners. Due to a higher ownership cost and priority of fast charging rate in a small amount of time, they are most suitable for use as roadside public charging stations for top-ups on long EV trips.
AC Car Chargers
AC chargers, like the Evnex E-Series, are Mode 3 charging equipment designed for regular home charging or charging at work. As they balance ownership cost with a charge rate that can fill up an electric car battery over longer parking periods.
Portable Car Chargers
plug-in charging leads (Mode 2) are used with a household socket and produce the lowest charging speeds. While they are typically provided with an EV, portable chargers are generally not recommended for everyday use. They rely on the integrity of the wiring in your home, which is not always suited for the high power demands that are typical of modern EVs.
AC & DC charge points come in different sizes:
- DC chargers typically range from 25kW to 350kW. In New Zealand, most are 50kW with some 300kW appearing at key locations.
- Fixed AC chargers range from 3.7kW to 22kW, with single phase 7.4kW being the most common in New Zealand.
How does my electric car’s onboard charger influence my charging time?
It is important to understand that with DC charging, energy is fed directly from the charging station into the vehicle's battery. On the contrary, AC charging requires the car to convert the AC to DC before being stored in the EV's battery. Therefore, when charging from an AC charger, the charging speed is constrained by the size of a car’s onboard charger, even though the AC charger may be capable of a faster charging speed.
As an example, you may have a three-phase 22kW AC home charger installed, but your EV can only convert a maximum of 6.6kW on a single phase via the onboard charger. Therefore, the highest charging speed you will see is 6.6kW. Although it may seem unnecessary to install an EV charger with a higher capacity than your vehicle supports, it makes sense to upgrade for potential safety features, smart charging options, and future-proofing purposes.
When planning to buy a charger for your electric car, it’s helpful to understand the maximum 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 (until you potentially upgrade your EV in the future).
The table below provides a guide to charging times. 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 as well if there are others waiting to use the public charger.
"There are three factors that determine how fast your electric vehicle will charge, firstly the speed of an EV charger, the maximum supported charging speed of the EV itself, and the vehicle's battery capacity."
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.