Units

Usage of numerous workplace charging stations from May to August 2013 at Facebook’s office campus in Menlo Park, CA was studied. The charging stations at this facility included alternating current (AC) Level 1-and AC Level 2-capable units and a direct current (DC) fast charger. The AC Level 2 charging units were the most heavily utilized, accounting for 83 % of the charging events, with 11 % of the charging events being performed using the DC fast charger. Drivers opted for AC Level 1 charging only 6 % of the time. The AC Level 2 charging units were used heavily during the work day, averaging 8.7 hours connected per cord per work day. Drivers tended to stay connected to Level 2 cords for around 4 hours or for around 9 hours – either half a work day or an entir