40 kWh regen per trip on 700 kWh total is very likely to have 98%+ charge/discharge efficiency. If it's doing 20 trips per day and a "day" is 8 hours (I suspec

40 kWh regen per trip on 700 kWh total is very likely to have 98%+ charge/discharge efficiency. If it's doing 20 trips per day and a "day" is 8 hours (I suspect it's actually more), then that's what- a ten minute trip? That would be charging at .34 C. A standard slow charge is between .2-.8 C.