What is the difference between 7kW and 22kW charging

It depends on the power input of the building which can be single-phase or 3-phase. Most residential buildings in Europe have single-phase input which supports a maximum 7kW charging output. This means that you can charge your vehicle up to 7kW per hour.  22kW is the maximum capacity of the Stuart charger, which means that you can charge your vehicle up to 22kW per hour with a 3-phase input. Note that the charging speed of fast chargers will depend on your car’s model, for this reason, not all vehicles might accept more than 7kW