A home charging session runs at the lowest active limit in the path. That can be the supply, commissioned wallbox current, cable coding, vehicle’s onboard charger, load manager or car setting. Compare phase current and input power first. Do not increase electrical limits until the installation has been checked.
Is the displayed power measured at the same place?
The wallbox can show AC energy entering the car while the vehicle shows DC energy reaching the battery. Conversion, electronics, battery heating and cabin conditioning use some input. The two screens need not match.
Record whether each number is instantaneous power, session average or energy in kWh. Confusing kW and kWh can make a normal session look slow. Also note whether the car is close to its charge limit.
Compare over several stable minutes after the session has started. The first moments can include communication, ramp-up and temperature management.
Is the car limited to one phase?
An 11 kW three-phase wallbox does not make every car use three phases. On a typical unit limited to 16 A per phase, a single-phase car can draw only about 3.7 kW. About 7.4 kW requires the wallbox and assessed circuit to support and be configured for 32 A on that phase, as well as a car that can accept it.
Similarly, a three-phase car may use only 16 A per phase and stop around 11 kW on a 22 kW wallbox. Plug-in hybrids often have lower onboard AC limits than the wallbox.
Check the exact vehicle version. Optional chargers and regional specifications can differ. Dashboard menus cannot enable power electronics the car does not contain.
Is the wallbox commissioned below its label?
The product nameplate states a maximum capability, not necessarily the installed setting. An electrician may commission a lower current to match the circuit, building connection or grid approval.
Load management can lower it further in real time. Review the configured site limit and installation record. If they are missing, ask the original installer or another qualified professional to inspect the system.
Do not treat the app slider as spare electrical capacity
Never raise a commissioned limit just because the cable and wallbox carry a larger label. The fixed wiring, breaker, protective devices, supply and local rules all need to support the change.
Is dynamic load balancing reducing power?
A load manager measures or estimates other building demand and leaves only available capacity for the car. Charging can slow when cooking, heating or hot-water loads run, then recover later.
Watch the charger allocation alongside household demand. If the pattern matches, the system may be working exactly as designed. Scheduling high-energy appliances at different times can improve charging without raising the supply limit.
Unexpected zero-current periods, phase imbalance or a limit that never recovers deserve installer review. Sensor direction, phase mapping and controller communication need correct commissioning.
Is the cable setting the limit?
Socketed wallboxes and cars read the charging cable’s current coding. A correctly coded 20 A cable cannot be used as a 32 A cable merely because the connectors fit. Portable chargers also advertise a maximum current to the vehicle.
Inspect the cable label and match it to the intended phases and current. Replace an unsuitable assembly with one complete correctly rated cable. Do not modify connector coding or join charging cables.
A damaged plug or poor connection may trigger reduced power or a stop. Discontinue use for unusual heat, discolouration or a repeated cable fault.
Could schedules or charge limits be involved?
A tariff schedule can pause charging or divide it into windows. Solar modes may wait for a minimum surplus. A vehicle departure timer and wallbox timer can overlap badly and leave little shared charging time.
Test one immediate session while preserving the original settings. If full expected input power appears, rebuild the schedule with only one device controlling start and finish where practical.
Check the vehicle’s current setting too. Some cars remember a reduced AC current by location after a previous weak-supply warning.
Does temperature affect home charging?
A cold or hot battery can use input power for thermal management and may limit what reaches the cells. The effect is vehicle-specific. Cabin preconditioning can also consume several kilowatts while connected.
Look at total wall input and battery-side increase over time. A warm cabin is not missing energy. Schedule preconditioning while plugged in when the manufacturer supports it, but allow enough time for both comfort and charging.
Persistent low AC input in mild conditions is more likely to point toward configuration, phase availability or a fault than normal battery taper.
How do you report slow charging clearly?
Record vehicle model and battery percentage, wallbox model, cable rating, timestamp, phase currents, input power, major household loads, settings and fault messages. Compare one session when the building is quiet.
This lets the installer distinguish a car limit from a lost phase, load allocation or configuration problem. “It should be 22 kW” is not enough; a phase-by-phase snapshot often is.
Slow charging has a cause. Find the active limit before changing any limit.
Frequently asked questions
Why does an 11 kW wallbox charge my car at about 7 kW?
The car may accept only single-phase AC. About 7.4 kW requires the wallbox and assessed circuit to support and be configured for 32 A on that phase; a typical 11 kW wallbox limited to 16 A per phase supplies about 3.7 kW to a single-phase car. Check phase-by-phase data and the exact equipment limits before assuming a fault.
Why does charging power fall when appliances turn on?
Dynamic load management may be protecting the building supply by allocating less current to the EV. That is normal when correctly configured. If the reduction is unexpected or charging repeatedly stops, ask the installer to review the measurements and commissioned limits.
Can I increase charger current myself?
Do not raise a commissioned electrical limit unless the charger instructions and responsible installer permit that change for the assessed circuit and supply. A larger number in an app cannot increase cable, protective-device or service capacity and may create an overload.
