kW vs kWh — what's the difference?
The two most-used terms in EV charging, and why confusing them leads to bad buying decisions.
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kW (kilowatt) measures power — the rate at which energy flows. Think of it like the speed of a tap: a 7.4kW charger fills your battery faster than a 3.6kW one, just as a wide-open tap fills a bucket faster than a trickle.
kWh (kilowatt-hour) measures energy — the total amount stored. Your EV's battery is rated in kWh: a BYD Atto 3 has a 60.5kWh battery; a Tesla Model 3 Long Range has 82kWh. This is the size of the bucket.
The simple formula
Charge time = Battery capacity (kWh) ÷ Charger power (kW)
A 60kWh battery on a 7.4kW charger takes roughly 8 hours to charge from flat. This is only an estimate — actual charging time can also be affected by the vehicle's maximum AC charge rate, charging losses, battery temperature, and site limits.
7.4 kW
Typical home wallbox speed (single-phase)
22 kW
Maximum AC speed (three-phase)
~30 km
Approx. range added per hour at 7.4 kW
~110 km
Approx. range added per hour at 22 kW
Note: Actual range added depends on the vehicle's efficiency and charging limit.
What does it cost to charge at home in Australia?
Charging at home can significantly reduce running costs compared with petrol, especially when you can use a lower-cost electricity period or your own solar.
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The cost depends on two things: your EV's efficiency (kWh per 100km) and your electricity rate (cents per kWh). Your charging cost depends on your electricity plan. Flat-rate, time-of-use, EV-specific and free/low-cost daytime plans can produce very different results.
| Electricity rate | Cost per 100km* | Full charge (60kWh) | Full charge (82kWh) |
|---|---|---|---|
| 15c/kWh (off-peak) | $2.25 | $9 | $12.30 |
| 25c/kWh (example) | $3.75 | $15 | $20.50 |
| 35c/kWh (peak) | $5.25 | $21 | $28.70 |
| Free (surplus solar) | $0 | $0 | $0 |
| *Assumes 15kWh/100km average EV efficiency. Full charge cost is simplified and does not account for charging losses. For surplus solar, the real cost depends on the feed-in tariff you give up. | |||
Practical tip: schedule overnight charging
How home EV charging actually works
What happens between the wall, the charger, and your car.
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Your home charger (technically an EVSE — Electric Vehicle Supply Equipment) doesn't charge the car directly. It provides a controlled AC power supply and communicates with the car's onboard charger, which then converts AC to the DC that fills the battery.
Your switchboard
A dedicated wall charger is connected to an appropriately rated circuit selected by the licensed electrician for the charger, the home and the available electrical supply.
The wallbox (EVSE)
Manages the flow of power safely, communicates charging parameters to the vehicle, and handles smart features like scheduling.
The car's onboard charger
Converts AC to DC and manages the final charge into the battery cells. The onboard charger limits the maximum AC charging speed.
Why your car's onboard charger matters
AC vs DC charging explained
The two fundamentally different ways electricity enters your EV's battery.
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Most home wallbox chargers use AC charging. The vehicle's onboard charger converts that AC electricity to DC for the battery. DC charging performs the conversion in the charging equipment and supplies DC directly to the vehicle battery, bypassing the onboard AC charger. High-power DC charging is most commonly found at public fast-charging stations, although specialised residential DC and bidirectional charging systems are now emerging.
| AC Charging | DC Charging | |
|---|---|---|
| Where | Home, workplaces and some public charging | Mostly public fast-charging networks; specialised home systems also exist |
| Speed | 3.6–22kW | Typically 50–350kW for public fast charging; residential DC systems are usually lower power |
| Conversion location | Inside the vehicle | In the charging unit |
| Typical cost to install | $1,000–$2,500 installed | $50,000+ (commercial) |
| Battery impact | Gentle on battery health | More heat; limit frequent DC use |
| Best for | Overnight home charging | Long-distance trips, quick top-ups |
Level 1, 2 and 3 charging
The international framework for categorising charging speed — and what it means in an Australian context.
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The Level 1/2/3 terminology originates in North America but is used globally to describe charging tiers by speed.
Source: 10A standard power point + travel EVSE
Range added: ~10 km/hr
Slow, but it can be enough for drivers who travel relatively short distances each day.
Source: Dedicated home wallbox on 32A circuit
Range added: 30–110 km/hr
A common choice when you want faster charging, smart features or more flexibility at home.
Source: Public DC fast charger (Tritium, BP Pulse, Tesla Supercharger)
Range added: 200–1,000+ km/hr
Primarily used for public and commercial fast charging. Specialised residential bidirectional DC systems are a separate emerging category.
Charging connectors — Type 2 and CCS2
Australia's standard connectors, and why you don't need to worry about compatibility.
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Australia has converged on two connector standards. Type 2 (also called Mennekes or IEC 62196) is the universal AC charging standard, used by every non-Tesla EV sold in Australia. Every home wallbox on this site uses Type 2. Tesla's own Wall Connector also now ships with a Type 2 connector (Gen 3+) and works with all EVs.
Type 2 (Mennekes)
Home charging- Use: AC home and public charging
- Max speed: Up to 22kW AC
- Vehicles: Most current Australian-market EVs
This is what your home wallbox uses.
CCS2 (Combined Charging)
- Use: DC fast charging (public)
- Max speed: Up to 350kW DC
- Vehicles: Most new EVs sold in Australia
Add-on to Type 2 port — same port, larger plug.
What about CHAdeMO?
Tethered vs untethered chargers
Should the cable be permanently attached to your charger or stored separately?
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A tethered charger has a fixed cable permanently attached — you plug straight into the car. An untethered charger has a socket; you need to provide and plug in a separate Type 2 cable.
Tethered
+ Grab and go — no fumbling with a cable
+ No loose cable to store or lose
+ Slightly cleaner installation
− Attached cable may be harder or costlier to replace
− More visible cable management
Convenient — no fumbling with cables when you arrive.
Untethered (Socket)
+ Cleaner appearance when not in use
+ Cable can be replaced separately
+ Flexible for multiple vehicles
− Must retrieve, connect and store the cable each time
− More steps to start charging
Clean appearance, and flexible for sharing or replacing cables.
Single-phase vs three-phase charging
The most misunderstood topic in home EV charging — and why most Australians don't need three-phase.
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Single-phase power supply is common in Australian homes. A typical 32A single-phase EV charging circuit is about 7.4kW. A suitable three-phase setup can support up to about 22kW AC charging at 32A per phase. However, actual charging power depends on the charger, circuit design, property supply, network requirements, load management, and your vehicle's AC limit.
A 22kW three-phase-capable charger cannot deliver 22kW from a single-phase supply. The available single-phase output depends on the charger model and installation. Check your switchboard or ask your electrician before assuming.
Single-phase homes (most Australians)
- Max charging speed: 7.4kW
- Adds ~30–40km range per hour
- Can charge a typical 60kWh battery overnight (an illustrative calculation)
- Many households can comfortably meet their normal driving needs
Three-phase homes (newer builds, some states)
- Max charging speed: 22kW
- Adds ~110km range per hour
- Can charge a typical 60kWh battery in ~3 hours (if vehicle supports 22kW AC)
- Worth unlocking if your EV and home support it
Upgrading to three-phase
Smart features worth paying for
Not all smart features add equal value. Here's which ones genuinely matter for Australian homes.
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Solar-aware charging
High — if you have solarMonitors your solar production and charges your EV using surplus solar rather than exporting it. Different chargers may use CT sensors, smart meters, or inverter communication. This lets you use more of your own surplus solar, though you give up the feed-in tariff you would have earned.
OCPP support
High — future-proofingOCPP can make it easier to connect a charger to compatible third-party charging-management platforms. The features available depend on the charger, the OCPP version and the platform.
Load balancing
High — older homesHelps keep EV charging within the configured capacity of the home by reducing charger output when other electrical loads are high.
App scheduling
Medium — on time-of-use tariffsSchedule charging for the lowest-cost period on your electricity plan. Most apps also track energy use and charge history.
RFID / access control
Low — for most homesAuthentication before charging starts. More relevant for shared parking, rental properties, or commercial contexts than typical single-home installations.
Solar panels and EV charging
How to use your solar system to charge your car — and the right charger features to make it work.
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Using surplus rooftop solar can make EV charging very low-cost because you're using energy that would otherwise be exported. The real economic cost also depends on any feed-in tariff you give up.
⚡
Fast (Grid)
Charges at full speed from the grid regardless of solar. Fastest possible charge; use when you need range quickly.
⚡🌤
Solar Assist (Eco)
Uses surplus solar first, tops up from the grid when solar isn't enough. Balances speed and solar self-consumption.
☀️
Solar Only (ECO+)
Only charges when surplus solar exceeds the minimum AC charging current. Many EVs require a minimum of about 6A. On a single-phase supply this is roughly 1.4kW. Three-phase charging can require around 4.2kW when all three phases are active, although some chargers can switch phases.
What you need for solar charging
- ✓ A charger with solar diversion support (myenergi Zappi, Ocular IQ, etc.)
- ✓ Solar-aware charging needs a way to measure or receive information about household import/export or available solar surplus. The method depends on the charger and energy system.
- ✓ Your solar inverter doesn't need to communicate directly with the charger — the CT clamp monitors net consumption at the switchboard
- ✓ Check specific compatibility before assuming your charger will work directly with a third-party solar system.
For GoodWe, Fronius, SolaX, Sungrow, Enphase, or Sigenergy households, choosing the matching brand's EV charger unlocks deeper integration through native inverter communication — going beyond CT clamp accuracy.
Tips for living with an EV in Australia
Practical habits that save money and protect your battery long-term.
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Follow the manufacturer charging limit
Many EVs recommend a lower daily limit such as around 80%, while some battery types use different charging routines. Follow your vehicle manufacturer's recommended daily charge limit.
Avoid leaving the battery very low
Avoid routinely leaving the battery very low for long periods, and follow the manufacturer's battery-care guidance.
Schedule for the cheapest period
Most home charger apps let you set a charge window. Schedule charging for the cheapest period on your electricity plan.
Precondition while plugged in
If your EV supports scheduled preconditioning, doing it while plugged in can reduce the amount of battery energy used to heat or cool the cabin before departure.
Get at least two installation quotes
Installation costs vary widely depending on the switchboard, cable run, and site complexity. Always get quotes from licensed electricians with EV charging experience.
Check your EV's max AC charge rate
A 22kW charger will not make a particular vehicle charge faster if the vehicle accepts only 7.4kW AC. Check the vehicle's charging limits.
Consider future charging needs
If you are planning for a future EV or a second charger, ask your electrician whether it makes sense to allow for future capacity while the installation work is being done.
Check for EV electricity plans
Check whether your retailer offers an EV tariff, managed-charging plan or other EV-specific option. Some offers require a smart meter or compatible charger.
Bidirectional charging: V2L, V2H and V2G
How energy stored in an EV battery can be used outside the vehicle.
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Bidirectional charging allows energy stored in an EV battery to be used outside the vehicle. Depending on the vehicle and equipment, this can include powering appliances, supporting a home or sending electricity back to the grid.
V2L (Vehicle to Load)
Vehicle-to-load powers individual appliances or equipment from the EV, usually through an outlet or manufacturer-approved adapter.
V2H (Vehicle to Home)
Vehicle-to-home allows a compatible EV and charging system to supply electricity to the home's electrical system.
V2G (Vehicle to Grid)
Vehicle-to-grid allows a compatible system to export electricity from the EV to the electricity network. This may require network connection approval and compatible retail arrangements.
Australia today
Bidirectional charging is developing quickly in Australia, but compatibility still depends on the vehicle, charging equipment, electrical installation, software and local network requirements. A vehicle supporting V2L does not automatically support V2H or V2G.
Before buying equipment for V2H or V2G, check current Australian support with the vehicle manufacturer, charger manufacturer and your local electricity network. Standards such as AS/NZS 4777.2:2020 Amd 2:2024 now include provisions relevant to Mode 3 and Mode 4 bidirectional EV charging, but network requirements still vary.