In a hurry? These are the fastest-charging electric cars

As Australia's electric car market grows, you’ll read more about kilowatt-hour (kWh) – the EV equivalent of L/100km.

That’s because the amount of power an EV battery can store dictates how far you can drive before needing to plug in for a recharge, just like the volume of a fuel tank.

But almost as important as how much electricity you can squeeze into a battery is how long it takes to do so.

Imagine living with a petrol-powered car that could carry enough fuel to drive between Melbourne and Sydney, but you could only fill the tank through a drinking straw.

That’s why it’s important to consider not just the range of an electric vehicle, but also the time it takes to charge it – particularly when you venture on long road trips that are beyond the driving range limits of an EV battery and require charging stops.

Here’s what the numbers mean and what you need to look for when shopping around for an electric car.

Related: How long does it take to charge an EV, and what does it cost?

The story you're reading here is all about the EVs with the fastest charging capability for those that need to get a move on.

But how long does it take, in general, to charge today's EVs? See our detailed explainers below.

What’s a kilowatt-hour (kWh)?

For most buyers, it's not necessary to know the physics and science behind a kilowatt-hour (kWh), any more than you need to understand the calculation of a combustion engine’s power figures.

Put simply, a kWh is a unit of energy just like a calorie or joule, but one that’s particularly applicable to electric vehicles and their batteries.

The higher the number, the more energy the battery can absorb through charging and then release when required to drive the vehicle.

Context, though, is far more important than equations. At the upper end of the spectrum, the BMW iX is available with a 112kWh gross battery, while at the opposite end of the spectrum, the Mazda MX-30 is 35.5kWh gross.

However, note that these figures are the total gross battery capacity. The actual net capacity that’s available for owners to use is lower – 105kWh and 30kWh respectively. That’s because manufacturers implement bottom and top ‘buffers’ to help protect the battery health and ensure safety.

For perspective, your smartphone battery can store about 0.005kWh – or a total of about 2kWh over the course of a year’s use.

Even though your smartphone only holds a relatively tiny amount of energy, it doesn’t need to charge for any more than about eight hours to fit most people’s daily routines. Plug it in at night, and it will be ready for another day’s use the following morning.

It can be different for cars, however.

If you’re going to be using an electric vehicle to retrace largely the same route each day, and you are confident its single-charge driving range is more than enough (typically 300 to 600 kilometres depending on the model), then you really only need to replenish enough for the next day via a three-pin trickle charging cable. After all, you don’t need to always fully fill up a fuel tank.

If you need to utilise the full range capability everyday, then you’ll need to install a Level 2 AC wall box to fully recharge overnight (about eight hours).

But, for those days when you chose to go the long way, add in extra errands or even embark on a road trip, charging times become paramount over battery capacity, as you may need to top up while on the run – just as you do in a combustion-powered car.

Audi's head of development of charging time and charging efficiency, Silvia Gramlich, highlighted the importance of battery charging speed and overall capacity.

"Customers should not just be interested in the maximum value of charging power, but rather how it progresses and may have to be reduced during a charging process, because otherwise the batteries – for physical reasons – heat up," she said.

"The crucial question for customers is: how many kilowatt hours can I recharge in what period of time?"

80 is the golden number

Charging a battery is a little like getting air into a pool floaty, where the most pressure is required to fill the very last bit.

That’s why EV manufacturers often refer to an 80 per cent charge time, as this offers the best ratio of range to time.

Importantly, it’s also the general rule of thumb to maintain good battery health for lithium-ion packs, as cells are more stressed at the top- and bottom-end. However, the emergence of lithium-iron-phosphate (LFP) cathodes generally allows regular 100 per cent charging without excessive degradation concerns. Car manufacturers have different charge limit recommendations, so follow the owner’s manual.

After about the 80 per cent point, charging speed slows dramatically – regardless of battery type – and, therefore, most owners would not wait at a public charging point for the remaining 20 per cent of the charge in return for the extra investment of time.

Charging speed is related to battery capacity and driving range – but not exclusively. That’s because there are two other key factors at play.

In those 30 minutes or less, I'm free...

These EVs list a claimed 80 per cent charge time of 30 minutes or less:

• Audi E-Tron GT
• BMW iX1
• Genesis Electrified G80
• Genesis Electrified GV60
• Genesis Electrified GV70
• Hyundai Ioniq 5
• Kia EV6
• Mercedes-Benz EQA
• Mercedes-Benz EQB
• Mercedes-Benz EQC
• Porsche Taycan
• Tesla Model 3
• Tesla Model Y

It's important to note these figures are based on the maximum charge rate for the vehicle and certain factors such as battery temperatures and the current state of charge can affect charging times.

As you can see from the table, charging speed is related to battery capacity and driving range – but not exclusively. That’s because there are two other key factors at play.

How the fastest-charging models secure a position at the top of the table

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Battery design

All EV batteries feature sophisticated active and passive cooling systems to manage the significant amount of heat generated by the rapid charging and discharging they incur when in use via the battery management system (BMS) software.

The cooling systems can also be reversed to warm the battery during very cold weather.

How efficiently the cooling system transports heat away from the individual battery cells can affect the charging speed. Initially, high charging speeds can slow dramatically if the heat builds up too fast, said Gramlich.

According to the German carmaker, the Q8 E-Tron’s cooling system design partly explains its superior sustained charge speed as illustrated in the below graph for the pre-update model, first released in 2018.

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Charging power (kW) and force (V)

Electricity is sometimes likened to water to explain its physics and behaviour, including current (measured in amps), which would be most like water’s flow speed and quantity, while voltage is more like the water’s pressure.

That’s the secret to Porsche, Hyundai, Kia and Genesis's rapid charging scores. Unlike most other EVs, which use up to 400 volts, models such as the Taycan, Ioniq 5, EV6, GV60, and Electrified G80 adopt a more advanced 800-volt class architecture.

That means the ‘pressure’ of charging electrons into the battery is higher, enabling more driving range to be pushed into the cells in a shorter time. It also has performance advantages, too, when drawing charge back out of the battery.

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AC⚡DC

It also applies to the amount of power applied by the charging system.

If all else fails, most EVs can be charged using a standard three-pin 240-volt household socket, but this most basic method is represented by extended charging times.

The limiting factor is not just the volts and amps as previously mentioned, but also the alternating current of household power (AC), which uses an onboard AC to DC inverter to juice the EV battery.

That’s why almost all manufacturers offer some form of DC (direct current) charging, which is substantially faster without the need to convert energy. Just how fast depends on the charging power limits of the EV model and charging station.

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Home and away

Home charging power ranges from the lowest 1.8kW rate to 22kW depending on the type of power you have at home.

A standard 10 amp three-pin domestic socket is the slowest; upgrading to a 15 amp outlet will boost charge times, while three-phase power via an installed Level 2 AC wall box is the ultimate home charging solution.

To go beyond this, specialist DC fast- and ultra-rapid charging stations are the only option and are normally limited to public/shared infrastructure. These stations up the ante allowing EVs to charge at the maximum rates – as long as the charger outputs the same or more than the model’s max input – as listed in the table below.

Maximum charge power rates range from 50kW up to 350kW DC depending on the model.

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Fastest-charging EVs in Australia by max rate

While not all carmakers disclose claimed 10 to 80 per cent charge times, a number of models can recharge in 30 minutes or less.

Other models take between 30 minutes to one hour or so.

Keep in mind that a high charge rate doesn’t necessarily mean that it’s the fastest – a small battery with a decent enough DC speed could be quicker to replenish than a large battery on an ultra-rapid charge rate.

Knowledge is power

Just as you should when considering any car purchase, arm yourself with the relevant information and have a list of all the things you need in your next car.

It doesn’t matter if it’s boot space in litres or battery charging speed and capacity.

Generally speaking, a large battery has the potential to charge faster, but only with the correct equipment.

Get your head around battery capacity in kWh, find out the charge times for the particular model you're interested in as above, and find out the charging options available at home and on the run using apps, such as PlugShare.

Of course, charging speed isn’t everything. If you plug in at home or work overnight, then you don’t need to charge so quickly – and frequent fast charging is unhealthy for batteries in the long-run.

Energy efficiency, features, practicality and aftersales provisions are also important, so a little research and homework will enable you to find the perfect EV to fit your lifestyle.