How fast an electric vehicle charges depends on the weakest link in the chain. For AC charging, which covers almost all home charging, that is either the power available from the charger or the rating of the car's own onboard charger, whichever is lower. For DC fast charging, the charger delivers power straight to the battery, and the limit becomes the battery's charging curve, which slows as the battery fills. Those three limits explain why a 22 kW wall box may charge a car no faster than a 7 kW one.

The basic numbers: volts, amps and kilowatts

Charging power is voltage multiplied by current. Australian homes have a nominal supply of 230 V per phase, which gives these common AC levels:

The range column assumes consumption of roughly 15-18 kWh per 100 km and about 10% charging losses, so treat it as a guide only. Larger or less efficient vehicles add fewer kilometres per hour.

AC charging: the car does the conversion

An AC wall charger, technically electric vehicle supply equipment, does not convert power. It checks the connection, tells the car the maximum current available and switches the supply on safely. The conversion from AC to DC happens inside the car, in the onboard charger.

That onboard charger has its own rating, and it caps AC charging regardless of the wall box. A car with a 7 kW single-phase onboard charger will draw no more than about 7 kW from a 22 kW three-phase unit. Some cars accept 11 kW three-phase, a few accept 22 kW, and some use only one phase even when three are available. The vehicle's specification sheet is the place to check before choosing a charger.

AC charging power is usually steady across most of the charge, because the onboard charger's limit sits well below what the battery could accept. It tapers only as the battery approaches full.

DC charging: the charger does the conversion

DC chargers contain large power converters and feed the battery directly, bypassing the onboard charger. Public DC chargers commonly range from around 50 kW to 350 kW, while home DC charging is uncommon outside bidirectional systems. With DC, the car's battery management system is in control: it tells the charger how much current it will accept from moment to moment, based on battery voltage, state of charge and temperature.

That produces a charging curve. Power is highest when the battery is fairly empty and warm, holds for a period, then steps down as the cells approach full, because pushing high current into nearly full cells risks damage. This is why DC charging times are usually quoted from 10% or 20% up to 80%: the final stretch to 100% takes a disproportionate share of the total time. Cold batteries also accept less power, which is why many cars warm the battery when navigating to a fast charger.

Practical charging times

Most driving does not require a full charge each night. The illustrative table below compares two common needs for a car with a 60 kWh battery, allowing for typical losses.

For many commuters, an overnight window on even a modest charger comfortably replaces a day's driving. Faster home charging matters more for long daily distances, for two EVs sharing one charger, or when charging is restricted to solar hours or off-peak windows.

Before choosing a home charging level, it helps to gather a few details:

• The car's onboard charger rating, and whether it accepts single-phase only or three-phase.
• Average daily distance, and how often longer trips happen.
• When the car is usually parked at home, especially during solar hours or off-peak windows.
• The home's supply: single-phase or three-phase, switchboard space and spare capacity.
• Other planned loads, such as a heat pump, induction cooktop or a second EV.

Single-phase or three-phase at home?

Three-phase charging only helps if the car's onboard charger can use it. Where it can, the benefits include faster charging and spreading the load across phases, which can suit homes with other large appliances. Three-phase also changes solar-matched charging. Chargers generally cannot run below a minimum of about 6 A, which is roughly 1.4 kW on one phase but about 4.1 kW across three phases, so a three-phase charger needs a larger solar surplus before it can start unless it can switch to single-phase operation.

Upgrading a home from single-phase to three-phase involves network approval and metering changes, and is usually worth it only when several large loads are planned. Any charger installation, and any assessment of whether the home's supply can carry it, must be done by a licensed electrician. How charging fits alongside solar and storage is explored in solar, EV and the smart home energy ecosystem, and unfamiliar terms are defined in the solar technology glossary.

Next steps

The Blue Energy Solar market lists a 7 kW Home EV Charger from $1,690 and an 11 kW Three-Phase EV Charger from $2,190, both supplied and installed. Prices are indicative and confirmed after a site assessment, which checks cable runs and supply capacity. To size charging around your solar and your driving, request a free assessment from Blue Energy Solar.

Frequently asked questions

Is it safe to charge an EV from an ordinary power point?

It can be, using the portable charging equipment supplied for the car, plugged directly into a power point in good condition on a suitable circuit. Charging draws high current for many hours, so avoid extension leads, double adaptors and worn outlets. If the home's wiring is old or the outlet feels warm, have a licensed electrician inspect it before continuing, or install a dedicated wall charger.

Does frequent DC fast charging wear the battery faster?

High-power charging creates more heat and stress than slow charging, so relying on it constantly can add some extra wear over time. Modern battery management and thermal systems limit this by controlling current and temperature. For most owners, charging mainly at home on AC and using fast chargers for longer trips is a sensible balance. Follow the manufacturer's guidance for your vehicle.

Can an EV be charged outdoors in the rain?

Yes, when the equipment is designed and installed for outdoor use. Charging connectors and outdoor wall chargers are built with weather sealing, and the charger does not energise the cable until it has confirmed a secure connection with the car. The installation still needs a suitable enclosure rating, correct protection devices and tidy cable management, all arranged by a licensed electrician.