## Common ground
All options describe electric vehicle charging stations, which supply power to electric vehicles.
## Options at a glance
**8504.40 – AC/DC conversion**
- **Defining trait:** Converts incoming AC power to DC for battery charging using rectifiers or transformers.
- **Typical examples:** Fast chargers, DC wall boxes, Level 3 chargers.
- **Best fit when:** The station actively changes electricity form (e.g., converts AC to DC).
**8537.10 – No conversion, only distribution**
- **Defining trait:** Supplies AC power without altering voltage or current; no rectifier or transformer.
- **Typical examples:** Basic AC charging stations, Level 1/2 home chargers with simple control.
- **Best fit when:** The device only switches, controls, or distributes power without conversion.
**9028.30 – Electricity metering**
- **Defining trait:** Primarily measures electricity consumption; may include charging functionality.
- **Typical examples:** Smart meters integrated into charging points, billing-enabled chargers.
- **Best fit when:** The main purpose is to measure and record energy use.
## Key differences
| Feature | 8504.40 (Conversion) | 8537.10 (Distribution) | 9028.30 (Metering) |
|-----------------------|------------------------|--------------------------|--------------------|
| Converts AC/DC | Yes | No | No |
| Contains rectifier | Yes | No | Optional |
| Measures energy use | Not primary | Not primary | Yes (main function)|
## How to choose
- Does the station convert AC to DC? → 8504.40
- Does it only supply AC power without conversion? → 8537.10
- Is measuring electricity consumption its main purpose? → 9028.30
## Overlaps & pitfalls
A charging station may include metering (9028.30) and conversion (8504.40), or control functions (8537.10) and metering. If multiple traits apply, prioritize based on the **main function**:
- Conversion → 8504.40
- Metering → 9028.30
- No conversion, only power delivery → 8537.10
If unclear, choose the option reflecting the device’s primary technical role