The main difference between 32A and 40A EV (electric vehicle) chargers is the speed or rate at which they charge an electric vehicle. A 32A charger can provide a maximum charging power of 7.4kW (kilowatts) to the vehicle, while a 40A charger can provide a maximum charging power of 9.6kW.

This means that a 40A portable charger can charge an EV at a faster rate than a 32A charger. Charging time is directly proportional to charging power, so a 40A charger will generally charge an EV faster than a 32A charger. However, it should be noted that the actual charging speed also depends on the capabilities and limitations of the electric vehicle on-board charger. Other factors, such as the EV's battery capacity and the type of charging cable used, can also affect overall charging time. It is always recommended that you consult the specific charging requirements and capabilities of your electric vehicle to determine the best charger for your needs.