Charging electric vehicles is not the same as refuelling a combustion vehicle, and the process has mired in myths that have dispersed throughout the media (no thanks to this year’s pre-election campaign by the Coalition, which claimed that EVs take 8-10 hours to charge).
Delta Electronics senior e-mobility and energy storage sales manager Matti Dinkelmeyer decided to dispel some of the myths surrounding EV charging at the Zero Emissions conference in Sydney last Thursday, and gave some useful insights into how EVs can be charged, and how quickly.
“While other countries have already embraced [electric vehicle] technology, Australia is still very much at the forefront of the rollout of electric vehicles,” Dinkelmeyer says.
“We have seen quite a development in the market, and particularly in the most recent election…a lot of focus of these debates has been around recharging capabilities and questions about how fast … fast charging takes.”
Dinkelmeyer says that transitioning to electric vehicle transportation will require a shift in behaviour for drivers from refilling the petrol tank every week or two, to “topping up” a charge instead – many of them on a daily basis.
“The paradigm shift now means that EV charging can happen anywhere and at any time, so any power socket becomes a refuelling station.”
“EV charging is easy – let’s face it, there’s only two types of fuels, there’s AC and DC,” he says.
|Charger Type||Electric Car Range added
|AC Level 1
|Up to 15km/hour|
|AC Level 2 “Wall Charger”
|Up to 40km/hour|
|AC Level 2 “Destination Charger”
|DC Fast Charger
50kW DC Fast Charger
|Around 40km/10 min|
|DC Rapid Charger
175kW DC Fast Charger
|Around 200km/ 15 min|
|DC Ultra-Rapid Charger
350kW DC Fast Charger
|Around 400km/ 15 min|
AC Charging explained
It’s useful to think of charging in terms of kilometres per hour – that is, how many kilometres of range can be added to an electric car battery an hour, or in the case of DC fast chargers, each 10-15 minutes (see chart above).
AC chargers are characterised by slower charging rates, and include rates from the so-called 2-3kW “trickle” or “granny” charging off your wall socket at home up to 22kW “destination chargers” that are often found at shopping centres or car parks.
“Each vehicle comes with a standard cordset, that’s usually 3.6kW of charging and can be plugged into any conventional wall socket anywhere, anywhere,” Dinkelmeyer says, adding that the impact on the electricity grid (a topic that also received a fair deal of warranted attention at the conference) is limited as the rate is so small.
While a standard wall socket trickle charger offers about 15km per hour of charge, a 7kW “wall charger” can be purchased from a number of different providers to supply an increased charging rate at home or for other applications like residential and office blocks – for many people these chargers may be the main charging location used.
“Dedicated residential or workplace chargers at 7kW again are limited impact on the grid,” Dinkelmeyer says, comparing such single phase chargers to an air conditioner.
These 7kW chargers offer 40km of range per hour of charge, and with modern EVs featuring charging schedule abilities, they can be set to charge within off peak hours to ensure benefiting from lower electricity rates.
As Laetitia Odini at Schneider Electric tells The Driven, in mature electric vehicle markets most EVs are charged at home.
“Overseas, the majority of the charging is done at home. People drive to work, then they return home,” Odini tells The Driven.
“Most of the penetration [of EV chargers] has really been in homes.”
But the option remains to top up wherever you stop – at a friend’s for example, says Dinkelmeyer.
“Day to day usage of your electric vehicle will become second nature to just plug it in anywhere making recharging a succession of top ups,” Dinkelmeyer says.
“You won’t want to wait until your battery is completely empty – you’ll just top up,” he says.
While home chargers are designed for single phase electricity connections, three-phase systems allow for a faster AC connection of up to 22kW.
“These are limited to workplace charging because the majority of properties in Australia are single-phase,” Dinkelmeyer says.
He points out that the ability of an electric vehicle to use higher AC charging rates is limited by its on-board rectifier.
“If your rectifier can only handle a maximum of 7kW then your 11-22kW charger is not really going to provide any benefits to the charge rate of the vehicle.”
DC Charging explained
Ranging from 50kW to 350kW charging rate, DC chargers offer drivers the option to get a faster boost of energy.
You would use a fast charger “when you have a particular operational requirement to quickly charge your car or for those odd occasions where you forget to plug it in to get yourself out of a pickle on the way to work,” says Dinkelmeyer.
“Fast charging [is for] when you’re doing longer trips or when you have particular operational requirements.”
While 50kW “fast chargers” can offer around 40 kilometres of extra range in 10 minutes, there are also much faster 150-175kW “rapid chargers” and 350kW “ultra-rapid chargers”, such as are being rolled out across the eastern seaboard of Australia.
These offer drivers the opportunity to stop for a shorter amount of time, general to travel from city to city or through regional areas.
“It’s important to install alongside highways because Australia has long distances, but most of these new EVs have more than enough range to cater for a few days driving without worrying about a flat battery,” says Odini.
Again, an electric vehicle’s ability to charge at these ultra-rapid rates depends on the vehicle’s on-board technology – check out our Models pages to explore the differences in charging rates of various electric vehicles available in Australia.
Charging in the future
Other charging solutions such as wireless charging are under development, however Dinkelmeyer says that there are usability and efficiency issues that are yet to be solved.
“There are a number of trial installations but energy efficiencies are still a concern,” he says.
“There is no uniform standard at this point in time. It requires additional hardware for the vehicle and in terms of usability, to have a maximum efficiency of that type of energy transfer you really need a very good alignment of the receiving end and the pad.”