Jan 31, 2020

Factors that influence charging power

The EVduty charging station, whose conformity to CSA and UL standards is certified by LabTest Certification Inc. for all variants, provides a maximum power of 7.2 kW (208-240VAC, 30 amps). Several factors – other than the charging station – can however influence charging power.

Does your car charge at less than 7.2 kW when plugged to an EVduty charging station? Here are the five most plausible explanations:

Your vehicle's on-board charger has a maximum power of less than 7.2 kW (see additional information below).
Your charging station was configured to limit power (in the case of an installation on a circuit of less than 40 amps for example).
Your EVduty charging station is configured for power sharing with a 2nd EVduty charging station and two vehicles are charging at the same time.
Your vehicle’s battery is full (or almost full) and this is a battery optimization phase.
There is a voltage variation in the distribution network*.

* At 240V, a 30 amp charging station can provide a maximum power of 7.2 kW (240V x 30A) but at 208V, the power will rather be 6.2 kW (208V x 30A). Voltage variations can occur especially during peak periods. Also, some commercial electrical installations deliver an industrial voltage of 208V.

ADDITIONAL INFORMATION: On-board charger

The power of what is called the "on-board charger" varies from vehicle to vehicle. This equipment receives alternating current (AC) from the charging station and converts it to direct current (DC) to recharge the battery. Fully electric vehicles are generally equipped with more powerful on-board chargers (6.6 kW or more), while plug-in hybrids often have less powerful chargers (3.3 to 6.6 kW).

The power of the on-board charger indicates the maximum number of kWh that can be transferred into the battery per hour of charging at 240V. This therefore influences the duration of a charging session. Take for example fully charging a battery with a capacity of 20 kWh. A vehicle whose on-board charger has a power of 3.3 kW will be full after 6 hours of charging (20 kWh divided by 3.3 kW) while a vehicle with an on-board charger of 6.6 kW (20 kWh divided by 6.6 kW) will be full after 3 hours.