Choose by dwell, not by the biggest number. The right class is the one whose output, multiplied by the stay your car park actually gets, covers the energy a visit needs — on the phases your supply has. A 7 kW post on a three-hour stay delivers more useful energy than a 22 kW post on a thirty-minute stop, so observe the stay first and let the arithmetic choose.
Key Takeaways
- The three classes are supply shapes: 7 kW single-phase, 11 kW three-phase at 16 A, 22 kW three-phase at 32 A.
- Delivered energy is power × the observed stay — run that arithmetic before choosing a class.
- The car’s onboard charger caps every session; the post’s rating is a ceiling, not a promise.
- Phase availability and concurrent load are site confirmations for the electrical design, never assumptions.
The Three Classes Are Three Supply Shapes
The ratings differ because the supply differs. The roughly 7 kW class is single-phase at 32 A; the 11 kW class is three-phase at 16 A per phase; the 22 kW class is three-phase at 32 A per phase. The U.S. DOT places Level 2 charging at 7–19 kW, adding 10–20 miles of range per hour; 22 kW is the three-phase class above that band’s stated top. Our explainer on single-phase vs three-phase charging works through the supply side. One ceiling applies at every class: the car’s onboard charger. A car accepting 11 kW AC takes 11 kW from a 22 kW post — the class is a ceiling, never a promise.
Run the Dwell Arithmetic
Delivered energy is power × time, assuming the car accepts the full rate throughout — an upper bound to compare against the energy your visitors need. The stays below are examples, not measurements of your site:
| Stay you observe | 7 kW class delivers up to | 11 kW class delivers up to | 22 kW class delivers up to | Specifier’s reading |
|---|---|---|---|---|
| 45 minutes | About 5 kWh | About 8 kWh | About 16 kWh | Short stays reward higher classes — where cars accept them and the supply feeds them |
| 2 hours | About 14 kWh | About 22 kWh | About 44 kWh | Covered at any class; the choice turns on turnover, not energy |
| 4 hours | About 28 kWh | About 44 kWh | About 88 kWh | Half-day stays are covered in full by the lower classes for most cars |
| 8 hours | About 56 kWh | About 88 kWh | About 176 kWh | Most batteries are satisfied long before the post is the limit |
Read it against your own evidence: observed stays, and the energy a visit needs to add. Our timing guide shows how long charging takes at 7, 11 and 22 kW from the driver’s side — the same arithmetic, read from the supply side.
Confirm the Phases Before You Specify
- Single-phase supply only: the roughly 7 kW class is the ceiling per post. More posts at that class may serve better than one oversized point; the total is a load decision for the electrical design.
- Three-phase available: 11 and 22 kW open up — but board availability is not capacity for every post at once; the concurrent total is what the design carries.
- Breaker sizing follows the NEC continuous-load rule: the breaker is 125% of the charger current — a 32 A charger takes a 40 A breaker. The rule scales every class.
- Nothing forces one class site-wide. Rows with different stays can be specified differently; the supply that totals them is designed once.
The Classes in the EVDANCE Range
Each class above maps to stated models. At roughly 7 kW single-phase, the EV-ACS3210E is a 32 A Type 2 portable charger at about 7 kW, and the EV-ACS3210T is its NACS counterpart at about 7.7 kW. At 11 kW three-phase, the ACS1605PE runs 16 A three-phase through a CEE five-pin plug. At 22 kW three-phase, the EV-ACT3204PE is a 32 A wallbox and the EV-ACS3205PE a 32 A portable on a CEE 32 A plug. Project teams can discuss a mixed-class layout through our commercial EV charging page or contact us.
Frequently Asked Questions
Is 22 kW always the best choice for a commercial car park?
No. It earns its capacity only where stays are short or visiting cars accept high AC rates, and it needs three-phase supply. On long stays the extra capacity idles; lower classes deliver the same energy before the car leaves.
What if our supply is single-phase only?
Then the roughly 7 kW class is the per-post ceiling, and the design question is how many posts the supply carries at once. Confirm it with the project’s electrical design — a supply upgrade is a separate project decision, not a charger feature.
Can different rows of one car park use different classes?
Yes. Specify each row against the stay observed there, and let the electrical design total the mix. The constraint is the shared supply, not uniformity.
Related Reading
- How Long Does It Take to Charge an EV at 7 kW, 11 kW and 22 kW?
- Single-Phase vs Three-Phase EV Charging: 7kW, 11kW and 22kW Explained
- EV Charging for Restaurants and Retail: Turning Dwell Time Into Visits
