smart #1: 7.4 kW vs 22 kW Home Charging in Australia
Quick answer: In Australia, the smart #1 Pro+ uses 7.4 kW AC charging, while Premium and BRABUS support up to 22 kW AC. smart says the 66 kWh battery can go from 10% to 80% in under seven hours on a 7.4 kW home wallbox and under three hours at 22 kW. The 22 kW figure is attractive, but it needs suitable three-phase power; many homes will be better served by a simpler 7.4 kW installation.
The same 66 kWh battery, very different AC hardware
| smart #1 variant | Battery | AC capability | WLTP range |
|---|---|---|---|
| Pro+ | 66 kWh | 7.4 kW | 420 km |
| Premium | 66 kWh | 22 kW | 440 km |
| BRABUS | 66 kWh | 22 kW | 400 km |
Because battery capacity is the same, the charging-time difference is mostly about onboard AC acceptance and the supply feeding the wallbox. Premium’s higher range does not come from a larger pack; smart attributes efficiency differences to configuration and technology such as the silicon-carbide inverter and heat pump. BRABUS sacrifices some range for performance.
What 22 kW means for an Australian house
Twenty-two-kilowatt AC typically relies on three-phase supply. Having the car capability does not mean the property can provide it without work. Before treating 22 kW as the default, check the existing supply, switchboard capacity and other large loads. If a 7.4 kW wallbox already replaces the day’s driving during the overnight parking window, the faster onboard charger may have no practical benefit at home.
Compare the 10–80% windows, not only full charge
smart’s own guidance gives a useful ownership comparison: under seven hours from 10% to 80% on 7.4 kW and under three hours on 22 kW for compatible variants. A driver who parks from 7 p.m. to 7 a.m. has enough time with either. A driver trying to fit a deep refill into a three-hour solar-export or off-peak window may benefit far more from 22 kW.
A daily-use calculation
If the car uses 16.8 kWh/100 km and drives 60 km, the battery energy used is roughly 10.1 kWh. Even allowing for charging losses, a 7.4 kW wallbox can replace that in well under two hours. This is why regular overnight top-ups change the charger decision: daily use rarely resembles a 10–80% laboratory window.
The 22 kW option can still be excellent
Three-phase owners who already have the supply can exploit very short charging windows without moving to DC infrastructure. That can be valuable for high-mileage households, commercial use or a home energy plan that concentrates charging around solar generation. The key is that the supply already makes sense for the property; installing major electrical infrastructure solely to save a few overnight hours may not.
DC charging does not depend on the home AC choice
smart lists 10–80% DC charging in under 30 minutes at compatible fast chargers. A Pro+ owner with 7.4 kW home AC still has access to rapid public charging for long-distance use. That separation means you can choose modest home hardware without giving up road-trip speed. It mirrors the principle in portable vs wall charging: home equipment should solve the home problem.
Which version makes sense for charging?
| Situation | Charging implication |
|---|---|
| Typical single-phase home | 7.4 kW can be entirely adequate |
| Existing three-phase home + short tariff window | 22 kW can add real flexibility |
| High-mileage fleet-like use | 22 kW shortens turnaround |
| Occasional road trips only | Public DC covers the exception |
Bottom line
The smart #1 shows why onboard AC power should be treated as a property-and-schedule feature. Premium and BRABUS can use 22 kW, but Pro+ at 7.4 kW can still replace ordinary daily mileage comfortably. Choose 22 kW when your electrical supply and charging window can exploit it; otherwise the simpler installation may be the better ownership decision.
Use solar and tariff timing to decide between 7.4 and 22 kW
Australian households increasingly combine EV charging with rooftop solar, batteries or time-of-use tariffs. A 22 kW charger can be very fast, but speed is not always the goal. During the day, a lower charging rate may track solar surplus more closely and reduce grid imports. Overnight, a short cheap-rate window can favor higher power. The best setting can therefore change by time of day. Owners with 22 kW capability do not need to use 22 kW on every session; flexible control is more valuable than maximum output alone.
Calculate the three-phase benefit in annual hours
Estimate how many times per year the car would actually benefit from charging faster than 7.4 kW. If a deep refill occurs every weekend and 22 kW saves roughly four hours, the annual time margin can be substantial. If most sessions replace only 10–15 kWh, both charger sizes finish quickly and the annual saving may be tiny. The case for three-phase charging should be built from session frequency, not from the difference between the maximum ratings.
Treat the variants as energy-management choices
Pro+ has the lower AC ceiling, while Premium and BRABUS can exploit three-phase 22 kW. That distinction may matter more to a high-mileage home than the small differences in WLTP range. A buyer with existing three-phase supply can obtain faster turnarounds without changing the property. A buyer on single-phase power should not assume the Premium or BRABUS requires a supply upgrade; the car can still charge at lower compatible rates when the infrastructure provides less than its maximum.
Measure successful departures
After a month, count how many departures started below the planned state of charge. If the number is zero with 7.4 kW, the faster option would not have improved readiness. If repeated late arrivals and early departures create shortfalls, higher AC power can solve a real schedule problem. This metric is more useful than comparing empty-to-full times because it reflects the household’s actual use.
smart #1 takeaway
Twenty-two kilowatts is a valuable capability for the right property, especially where three-phase power already exists. It is not a requirement for successful smart #1 ownership. Choose the charging rate that fits the home energy system, tariff and parking schedule, then use public DC charging for the exceptional long-distance day.
Use an Australian tariff example to value 22 kW
Assume a household has a three-hour super-off-peak window. At 7.4 kW, the charger can draw up to 22.2 kWh from the grid in that period before losses; at 22 kW it can draw up to 66 kWh, which is around the smart #1 battery’s headline size. If an ordinary day uses only 12 kWh, both options finish cheaply. If a high-mileage driver frequently returns with a 40–50 kWh deficit, 22 kW can keep much more of that refill inside the discounted window. The value of three-phase charging therefore comes from tariff and schedule interaction, not merely from a shorter 10–80% time.
Solar surplus may favor slower charging during the day
Maximum power is not always the cheapest power. A rooftop solar system producing 5–8 kW of surplus may pair more naturally with a moderated charging rate than with 22 kW, which could import a large amount from the grid. Owners with a smart wallbox can vary charging power: follow solar during daylight, then use a higher three-phase rate when the cheap overnight period begins. This flexibility is often more valuable than operating at the maximum rate every time the car is plugged in.
Calculate annual “missed departure” events
For one month, note every morning the car leaves below the intended state of charge. If 7.4 kW produces zero missed targets, upgrading solely for speed solves no readiness problem. If a high-use household records several misses because late arrivals collide with early departures, 22 kW has a measurable operational benefit. Extrapolate the frequency over a year and compare it with the electrical upgrade cost. This converts a vague desire for faster charging into a countable convenience metric.
Variants should not force a property upgrade
Premium and BRABUS can exploit 22 kW AC where compatible three-phase infrastructure exists, but they can still charge from lower-power AC equipment. A buyer should not reject a trim—or rebuild the property—simply because the car supports a higher maximum. Start with the supply already available, determine whether it meets the daily energy target, and consider upgrades only if repeated use proves the limitation. Vehicle capability is a ceiling, not a minimum household requirement.
smart #1 home-charging conclusion
The strongest case for 22 kW is an existing three-phase home with high daily mileage, a narrow low-cost tariff window or frequent short turnaround. The strongest case for 7.4 kW is ordinary daily mileage with long overnight parking and no recurring readiness problem. Use solar, tariff timing and actual departure performance to choose the rate. That produces a charging system designed around the household rather than around the largest number on the specification sheet.
Treat 22 kW as flexible capacity, not a permanent setting
Where the home and wallbox support it, the owner can still choose a lower charging rate when solar output, battery storage or household demand makes that more economical. The value of 22 kW is therefore optional headroom: it can shorten a rare turnaround without forcing every routine session to draw maximum power. A good energy-management setup can charge slowly during solar-rich hours, pause during household peaks and accelerate inside a cheap overnight window. This flexible behavior is a stronger reason for three-phase capability than simply advertising the shortest possible full-charge time.
Sources and verification
Manufacturer references used for the specifications above:
Last verified: September 6, 2026.