DarkStar
Well-known member
CHAdeMO is actually kinda the opposite of J1772. Instead of the EVSE telling the car the maximum amperage it can draw, the car tells the DC Quick Charge the voltage and amperage to send to the car. As the vehicle charges it sends new signals to the DC Quick Charger to reduce the amperage.GroundLoop said:planet4ever said:Doesn't make sense to me. How does the charging station know what the charge states of the battery cells are? I suppose it could make a rough guess based on a drop in current flowing. However, the Battery Management System in the car knows much more about the charge states, so if an 80% shutoff is occurring it would make more sense to me for the BMS to shut off to prolong battery life.
Unlike AC L2 charging (J1772), there is data communication between the car and the DC Charger. I don't know what the protocol for that data is (yet), but it likely shares the state of charge and other details useful to the DC Charger in ending the charge.
The current way it works is you'll go from 0-80% in about 25 minutes. It will take an additional 15-20 minutes to go from 80-100%, providing a 0-100% charge in 40-45 minutes!
What people are forgetting is that the DC Quick Chargers do exactly what the internal charger does on the vehicle, except they can provide a higher amperage (same voltage). Personally, Nissan should offer additional control so I could punch in that I want a certain percentage of charge in a specified time-frame. No need to charge at a 2C (a designation of a lipo charge rate) rate when 1C (half the amperage of 2C) will work for me.