EV charging splits into two modes: AC (alternating current) and DC (direct current). The distinction affects maximum power levels, charging times, hardware cost, and how a CSMS models and controls charging sessions. CSMS developers writing smart charging logic, billing calculations, and simulator configurations need the numbers.
AC charging
In AC charging, the charger supplies AC power to the vehicle. The EV's onboard AC/DC converter (the onboard charger) does the conversion, which means the maximum AC charging speed is limited by the onboard charger's capacity, not only by the charge point.
Common AC power levels:
- 3.7 kW. Single-phase 16 A at 230 V. Typical for home charging on a standard socket or Schuko.
- 7.4 kW. Single-phase 32 A at 230 V. Common for home wallboxes and workplace chargers.
- 11 kW. Three-phase 16 A at 400 V. Standard for three-phase home and commercial installations.
- 22 kW. Three-phase 32 A at 400 V. The maximum AC level supported by most EVs with a three-phase onboard charger. Many vehicles cap at 11 kW.
Most public AC charge points are 7.4 kW or 22 kW. The actual charging rate is always the minimum of what the charge point can supply and what the EV can accept.
DC fast charging
In DC charging, the charger itself contains the AC/DC converter. It supplies DC current directly to the battery, bypassing the onboard charger. That removes the onboard charger as a bottleneck and enables much higher power levels.
Common DC power levels:
- 50 kW. Entry-level DC fast charging, common at motorway service stations and older public networks. Charges most EVs from 20% to 80% in 30 to 60 minutes.
- 100 to 150 kW. Mid-range DC charging, common in newer public installations.
- 250 kW. High-power DC charging for vehicles capable of accepting it (Tesla Model 3/Y long range, Hyundai IONIQ 6, and similar).
- 350 kW. Ultra-fast DC, supported by high-end infrastructure (Ionity, some Tesla V3 Superchargers). Few production vehicles can accept more than 270 kW today.
As with AC, the actual power delivered is the minimum of what the charger offers and what the vehicle's battery management system requests.
Why this matters for CSMS developers
Power levels affect CSMS logic in several ways. Smart charging profile limits have to sit within realistic bounds: a ChargePointMaxProfile of 500 kW on a 7.4 kW AC charger is valid OCPP but meaningless. Billing calculations based on energy delivered (kWh) depend on accurate power and duration data. SOC-based session management behaves differently at 7.4 kW than at 150 kW.
When testing your CSMS with a simulator, configuring the station with realistic power values produces meter readings that exercise your billing and smart charging logic against plausible data. A 350 kW DC station and a 7.4 kW AC station produce very different MeterValues patterns, and can expose different bugs in your CSMS.
SimItNow lets you configure per-station power levels and EV battery capacity when creating virtual stations, so your test scenarios match the hardware your CSMS will interact with in the field.
Create a free SimItNow account and simulate AC and DC charging scenarios against your CSMS.