A practical guide to charger power, household supply, solar integration, smart controls and compliant installation
The short answer Choose the charger that suits your vehicle, daily driving and electrical installation. The highest power rating is not automatically the best choice.
A home EV charger should make daily charging simple, safe and predictable. The right choice is not just the charger with the biggest number on the box. Your car may accept less power than the charger can supply. Your home may not have enough spare electrical capacity. Solar and backup systems can add another layer to the design.
For many South African homes, a properly designed 7.4 kW single-phase charger is more than enough. An 11 kW or 22 kW unit can make sense, but only if the car, the electrical supply and the installation can use it. That is where we start before recommending a product.
Start with the vehicle
A home wallbox supplies AC power. The car's onboard charger converts it to DC for the battery. That onboard charger sets the car's maximum AC charging speed. A larger wallbox cannot push more power through the car than it is designed to accept.
Many lower-cost Chinese EVs, and quite a few European models, accept about 6.6 kW to 7.4 kW AC. Some are limited to single phase. Put one of these cars on an 11 kW or 22 kW three-phase wallbox and it will still charge at the car's lower limit.
Other cars can use both supply arrangements. The Volvo EX30 is a good example: roughly 7.4 kW on single phase and up to 11 kW on three phase. A smaller group of cars can use the full 22 kW from a three-phase wallbox. Always check the exact model and derivative. Specifications can differ within the same vehicle range.
Before selecting a charger, confirm the following in the vehicle manufacturer's specifications:
- maximum AC charging power
- whether the vehicle accepts single-phase or three-phase AC charging
- the charging connector used by the vehicle
- any current or phase limitations that apply to the specific model or derivative
South Africa has standardised in practice on Type 2 connectors for AC charging and CCS2 connectors for DC charging. The connector type and charging rate are separate issues, so check both. See AC vs DC EV Charging for the practical differences.
Match the charger to the household supply
Next, look at the house. A 7.4 kW single-phase charger can draw up to 32 A for hours at a time. That is a serious continuous load, especially when the geyser, oven, pool pump or air conditioner is also running.
A three-phase charger does not turn a single-phase house into a three-phase house. An 11 kW or 22 kW installation normally needs a suitable three-phase supply, spare capacity on all three phases and a car that can use it. A municipal supply upgrade can add cost, paperwork and delays.
| Charger rating | Typical AC supply | Approximate current | When it may suit a home |
|---|---|---|---|
| 3.6 kW | Single phase | 16 A | Low daily mileage, plug-in hybrids, or a capacity-limited property |
| 7.4 kW | Single phase | 32 A | A common match for vehicles limited to roughly 6.6 kW to 7.4 kW AC |
| 11 kW | Three phase | 16 A per phase | A three-phase property and a vehicle that can benefit from 11 kW AC |
| 22 kW | Three phase | 32 A per phase | A high-capacity installation and one of the vehicle models that can use 22 kW AC |
These figures are nominal. Actual charging power varies with voltage, the vehicle, charger settings, temperature and battery conditions. For a closer comparison, see 7.4 kW vs 11 kW vs 22 kW EV Chargers.
Size for the driving you actually do
Do not size the charger around a completely empty battery unless that is how you actually drive. Most cars come home with plenty of charge left. If a normal day uses 12 kWh, the charger only needs to put back about 12 kWh, plus the charging losses, before the next trip.
A simple planning estimate is:
Charging time in hours ≈ energy to add in kWh ÷ actual charging power in kW
At a real 7 kW, adding 21 kWh takes about three hours before allowing for losses. At 3.6 kW, it takes about six hours. Both can work comfortably overnight for many drivers.
See How Long Does It Take to Charge an EV at Home for charging-time examples.
Higher charging power can reduce energy losses
Faster supported AC charging can sometimes be more efficient as well as quicker. Independent testing across several EVs found that efficiency often dropped when the onboard charger ran far below its rated power. In that study, efficiency fell below 85% when some cars charged at less than about 25% to 40% of their rated AC power.
The main reason sits inside the car. The onboard charger's semiconductors have their own efficiency curve, while pumps, fans, controls and battery conditioning keep consuming power for as long as the session runs. On a correctly designed circuit, these conversion and auxiliary losses can outweigh the extra cable loss at the higher current.
That does not mean faster is always better. Every car behaves differently, and cable losses still rise with current. It simply means that charging losses are vehicle-specific. We should not assume that turning the current down will always save energy.
Decide which smart functions matter
A basic wallbox may be all you need if the home has enough spare capacity and the car handles the charging schedule. Smart functions earn their keep when the supply is tight, household demand changes through the day, solar is involved or you want to see exactly what the car is using.
Useful home-charging functions can include:
- adjustable charging current
- scheduled charging and off-peak timing
- energy monitoring and charging history
- app or RFID access control
- dynamic load management that reduces EV demand when the home approaches its limit
- solar-surplus charging when compatible metering and controls are installed
Read the small print on these features. Load management or solar charging may need an extra energy meter, CT clamp, gateway, communication cable or cloud service. The whole system must be compatible; the feature name on the box is not enough. Some systems may also need bespoke integration, particularly where the charger must communicate with home-automation equipment or equipment from different manufacturers.
Read Smart EV Chargers Explained and EV Charger Load Management Explained before paying for features you may not need or assuming a charger can perform functions that require extra hardware.
Treat solar and backup power as a system
Having solar does not automatically make the EV charger solar-aware. The charger needs to know what the house is using, what the solar system is producing and whether power is flowing to or from the grid. It then needs a reliable way to adjust the charging current.
Where the charger connects matters. A high-power charger is usually placed on the main or non-essential side of a hybrid system unless the inverter and battery were specifically designed to carry it. Putting a 7.4 kW charger behind a 5 kW inverter does not make the inverter bigger.
We check the inverter's grid input, pass-through rating, essential and non-essential layout, battery limits, operating modes and earthing. Solar control and load management help manage the power. They do not replace proper electrical protection.
For a detailed explanation, see Can I Charge My EV From Solar.
Choose the hardware only after the installation is assessed
An EV charger is a heavy, long-duration electrical load. It is not something to add casually to the nearest available circuit. Cable size depends on the route, distance, installation method, ambient temperature, grouping, voltage drop, protection and fault conditions — not only the charger's kW rating.
The final design may need a dedicated circuit, the correct breaker and residual-current protection, isolation, surge protection, suitable earthing and enough room in the DB. The exact arrangement depends on the charger and the site.
In South Africa, this work must be inspected, tested and certified by the appropriately registered person. The charger circuit must be covered by a valid Certificate of Compliance and test report. Your municipality or supply authority may have extra requirements.
See EV Charger Installation Requirements in South Africa for the installation and compliance checklist.
Buy equipment intended for years of daily duty
Buy a charger with a proper factory warranty and a clear local support route. Quality domestic units commonly start at three years, with some warranties extending to four or five years. The Teltonika EVC 2, for example, carries a 36-month factory warranty that can be extended to 60 months. Always confirm the terms for the exact unit supplied in South Africa.
Do the maths. Four hours per night, five nights a week, is about 1,040 hours under load every year. Over five years, that is roughly 5,200 hours and 1,300 charging sessions. Every session operates the internal contactor and adds another mechanical cycle to the plug and socket. The cable, terminals, electronics and enclosure all have to keep doing their job.
A cheap charger stops being cheap when the warranty is vague or there is nobody local to help. Compare the written warranty and support path with the same care as the power rating and smart features. We supply proven options such as Autel and Teltonika, then match the product to the job.
Portable charger or fixed wallbox
A portable charger is useful for travel or occasional low-power charging, provided the socket and circuit are suitable. It does not prove that an ordinary household socket is safe for a heavy load every night.
A fixed wallbox gives you a more controlled setup: a dedicated circuit, a permanent cable position, adjustable current and, where needed, access control or smart functions. The right answer depends on how often you charge and what the installation can safely support.
Plan for the next vehicle without overbuilding
Future-ready does not automatically mean 22 kW today. It may mean choosing an adjustable charger, installing the right conduit or cable route, leaving space in the DB and allowing for future load management or solar control.
A 22 kW-capable wallbox can sometimes be commissioned at a lower current for now. The circuit and protection still have to match the approved design. A software setting cannot fix an undersized cable or unsuitable installation.
A practical home charger checklist
- Confirm the vehicle's maximum AC charging rate and phase capability.
- Estimate the energy normally used each day and the available charging window.
- Identify whether the property has single-phase or three-phase supply.
- Measure or assess spare capacity while major household loads are operating.
- Review the distribution board, cable route, earthing and required protection.
- Check the inverter, backup and solar topology where applicable.
- Select only the smart functions that the complete system can support.
- Confirm equipment location, weather exposure, cable reach and access control.
- Obtain installation testing, documentation and an appropriate Certificate of Compliance.
The NevGridSolutions approach
We start with the car, the property and the energy system. If a dealership-supplied wallbox is suitable, we can assess how to integrate it. If the supply is tight or the home has solar and battery storage, an adjustable charger, dynamic load management or a different connection point may be the better answer.
The goal is simple: a charger that works properly with the home, covers the driver's daily needs and leaves a sensible path for later upgrades.
Talk to NevGridSolutions
NevGridSolutions can assess your vehicle, household supply, DB, solar or inverter system and installation route before recommending the hardware.
065 556 4000 | info@nevgridsolutions.co.za | www.nevgridsolutions.co.za
Frequently asked questions
Is a 7.4 kW charger enough for home use?
For many South African drivers, yes. A 7.4 kW charger can replace a substantial amount of energy overnight, provided the vehicle accepts that rate and the property has enough electrical capacity.
Can I install an 11 kW charger on single phase?
A typical 11 kW AC wallbox uses a three-phase supply. A single-phase property normally cannot deliver 11 kW in that configuration, even if the charger carries an 11 kW rating.
Will a 22 kW charger charge every EV faster?
No. The vehicle's onboard AC charger sets the maximum AC charging rate. Many vehicles accept less than 22 kW.
Can my home EV charger use solar power?
Yes, if the solar capacity, connection topology, metering and controls support it. Solar-surplus charging usually needs compatible monitoring and adjustable charging control.
Do I need a Certificate of Compliance for a home EV charger?
Electrical installation work must be inspected, tested and certified in line with South Africa's Electrical Installation Regulations. The charger addition or alteration should be covered by the appropriate Certificate of Compliance and test report.
What warranty should a home EV charger have?
Look for a factory-backed warranty with a clear local support route. Established domestic charger ranges commonly offer three years, while selected products offer four or five years. Always confirm the exact model, covered components and local terms before purchase.
Talk to NevGridSolutions
NevGridSolutions can assess your vehicle, site, supply capacity, DB, solar or inverter system and installation route before recommending the hardware.