zappi is an AC charger for electric vehicles, designed to meet the requirements of the International Standard IEC 61851-1 "Electric vehicle conductive charging system - Part 1: General requirements"
This standard states that EV charging current can vary between 6A and 32A (subject to any limitations on the supply). As power is related to current, this means that the power supplied to the EV when it is charging will be in the following range (based on a nominal supply voltage of 230V, line-neutral)
| Charge Mode | Minimum Charge Power | Maximum Charge Power |
| Single Phase | ~1.4kW | ~7.3kW |
| Three Phase | ~4.2kW | ~22kW |
These restrictions have an impact on the three phase zappi in ECO/ECO+ mode:
- If zappi is in single phase mode, then the charge rate will not go above ~7.3kW even if there is more surplus power available from local renewable generation
- If zappi is in three phase mode, then the charge will stop if the available surplus generation drops below ~4.2kW (depending on the setting of the "Minimum Green Level")
With the V5 firmware, zappi will now switch automatically between single-phase and three-phase charging as the surplus power available varies during the day. See: Automatic Phase Switching
Note: When a three phase zappi is in FAST mode or Boosting, all three phases will be used provided the EV supports three phase charging.