If you are asking what size home EV charger you need in Ireland, start with the job it must complete each day. A 22 kW wallbox is not automatically more useful than a 7.2 kW unit: if the car accepts only 11 kW AC, it will charge at no more than 11 kW. If the home has little spare capacity while heating and cooking loads are running, the charger may also need to reduce its demand.
The useful charging rate is therefore the lowest limit in the chain: the home supply, dedicated circuit, charge point, cable and the vehicle’s onboard charger. Daily kilometres and the number of hours parked at home tell you how much of that maximum you actually need.
The short answer
- 3.6–3.7 kW can cover low daily mileage, plug-in hybrids and long overnight stays.
- 7.2–7.4 kW is a practical single-phase class for regular overnight charging when the car and home support it.
- 11 kW is useful when three-phase supply and an 11 kW AC onboard charger are both available.
- 22 kW delivers its full benefit only to a car that accepts 22 kW AC and a property designed to supply it.
3.6, 7.2, 11 or 22 kW: what changes day to day?
Product labels often use 3.6 and 7.2 kW, while technical comparisons based on 230 V commonly show about 3.7 and 7.4 kW. This guide treats 3.6/3.7 and 7.2/7.4 kW as the same practical classes; the exact configured output still depends on the equipment and installation.
A kilowatt (kW) is a rate of energy transfer. A kilowatt-hour (kWh) is an amount of energy. The simplest comparison is: charging time ≈ energy to add ÷ power actually received.
| Power class | Typical supply | Where it can fit | Check first |
|---|---|---|---|
| 3.6–3.7 kW | Single phase | Low mileage, PHEV, long parking window | Dedicated circuit, protections and socket/charge-point suitability |
| 7.2–7.4 kW | Single phase, up to about 32 A | Routine overnight home charging | Vehicle AC limit and spare household capacity |
| 11 kW | Usually three phase | Higher daily energy or a shorter parking window | Three-phase availability and 11 kW onboard charger |
| 22 kW | Three phase | Compatible vehicle and a genuine need for rapid turnaround | Vehicle, connection, circuit and load-management limits |
Check the car’s AC onboard charger before the wallbox
During AC charging, the car’s onboard charger (OBC) converts the incoming electricity for storage in the battery. Its maximum AC rating is a hard ceiling. A car advertised with very fast DC public charging may still accept only 7.4 or 11 kW AC at home.
Use the specification for the exact model year, battery and trim. Options can differ within the same vehicle family, and a cable or software setting can introduce another limit.
A 22 kW wallbox connected to a car with an 11 kW AC limit remains an 11 kW solution for that car.
Check the Irish home, not just the charger rating
The distribution board, earthing, protective devices, cable route and the loads already used by the home all matter. The Sustainable Energy Authority of Ireland recommends an electrical survey before choosing the final car-and-charger combination. Its home-charger scheme also requires electrical work to be carried out by a Safe Electric registered electrical contractor.
This does not mean every home needs the same upgrade. It means charger power should be a result of the site assessment. A long cable route, limited spare capacity or simultaneous heat-pump and cooking demand can change the appropriate design.
Estimate the energy you actually replace each day
Home charging is rarely a full-battery test. Most nights you replace the energy used since the previous charge.
- Record normal daily distance. Use a representative week, not the longest annual trip.
- Use real vehicle consumption. Take the dashboard average in kWh/100 km where possible.
- Calculate energy used. Distance × consumption ÷ 100.
- Divide by parked hours. Add a sensible allowance for losses and cold-weather variation.
At 18 kWh/100 km, a 60 km day uses about 10.8 kWh. Even after allowing for losses, that is a different problem from refilling a 60 or 80 kWh battery from empty. If the car is parked for ten hours, moderate power may complete the task comfortably.
Choose the level that changes your routine
3.6–3.7 kW
Consider this class when daily energy is low and the vehicle remains parked for many hours. It can suit a plug-in hybrid particularly well.
7.2–7.4 kW
A balanced overnight option when the car accepts it and the electrical survey confirms that the home can support it.
11 or 22 kW
Choose higher AC power only when vehicle compatibility, supply and a repeatable time-saving need all line up.
Ask how often a higher level would alter the next departure. If the car already finishes by morning at 7.2 kW, 11 kW may shorten a process that was not constraining you. If two high-mileage journeys are separated by a short stop, the extra power can have real value.
Use dynamic load management for a changing household load
Dynamic load management follows household demand and adjusts vehicle charging to the capacity left over. When an oven, immersion heater or heat pump draws more power, charging can be reduced; when home demand falls, it can rise again within the configured limits.
It does not increase the vehicle’s OBC limit and does not replace correct circuit design. Its purpose is to allocate available power more intelligently and reduce avoidable overloads.
Match the Rheidon setup after the diagnosis
Once the car, property and daily requirement are clear, compare the appropriate fixed charging hardware and power-management option.
WB500 wallbox range
Use the collection to compare WB500-7K2, WB500-11K and WB500-22K configurations. Select the class validated for the vehicle and installation rather than treating the largest number as the default.
AC500 smart load balancer
Paired with a compatible WB500 setup, AC500 can adjust charging as other household loads change. Final settings must follow the electrical assessment.
Use this decision order
- Find the car’s maximum AC onboard-charger rating.
- Confirm the property supply and installation condition.
- Estimate energy used on a normal day.
- Compare it with the usual home parking window.
- Have the dedicated circuit and protections assessed by a registered contractor.
- Add dynamic load management where simultaneous household demand makes it useful.
The right charger is the one that restores the energy you need before the next trip without asking the home or the car to do what it cannot support.
Frequently asked questions
Is a 7.2 kW home EV charger enough?
Often, yes, if the car is parked overnight and 7.2–7.4 kW can replace the energy used during the day. Calculate daily kWh and check the car and installation rather than judging by battery size alone.
Do I need an 11 kW charger at home?
Only if the car accepts 11 kW AC, the property can support the required supply and the shorter charging window solves a regular problem. Otherwise the additional rating may remain unused.
Will a 22 kW wallbox always charge twice as fast as 11 kW?
No. The car must accept 22 kW AC and the site must deliver it. An 11 kW OBC caps charging at 11 kW, regardless of the wallbox label.
What is the difference between 3.6 and 3.7 kW?
They are commonly used labels for approximately the same practical single-phase class. The displayed value depends on nominal voltage, current and product convention. The same applies to 7.2 and 7.4 kW.
Should I increase my home electrical capacity?
Not automatically. First assess actual peak demand and the available margin. Depending on the property, an upgrade may be justified; in other cases dynamic load management can share existing capacity.
Who should install a home charger in Ireland?
SEAI states that electrical work under its home-charger scheme must be completed by a Safe Electric registered electrical contractor and comply with Ireland’s National Rules for Electrical Installations.
Sources and references
- SEAI — Charging an Electric Vehicle: home assessment and installation guidance.
- SEAI — Electric Vehicle Home Charger Grant: current scheme and registered-contractor requirements.
- Renault Ireland — charging solutions: example of a vehicle’s AC onboard-charger limit.
- Rheidon WB500 range and AC500 product page: product functions referenced.
