Does scheduled charging wait to charge until necessary (reach target % right at departure time)?
Question in the title.. can't seem to find an answer to this by googling but I also may just not have the right terminology. I'm going to be charging up the car for a road trip and want to get to 100% when we depart in the morning. I don't want to let it sit at 100% too long overnight (charger is 48A so it goes quick).
If I set a scheduled departure time (and I guess you also have to set preferred off-peak hours), will it wait to start charging until it calculates that it needs to in order to hit 100% at or around the departure time? Or will it start charging as soon as it hits off-peak hours, basically treating the departure time as a "no later than" rather than a target time?
Posted Aug 28, 2023, 6:38 PM UTC
13
The car has no way of knowing what the charge rate is going to be: did you plug in the slow charger or the fast one? Therefore it has to assume the charge rate will be slow and it just makes sure that the car is charged ASAP while (usually) honoring the off peak times. The departure time is more for setting the interior cabin temp so that you are comfortable at departure.
That is helpful! But to be fair, the car DOES know what it's plugged into. The EVSE "advertises" it's max power capability to the car, which is how the car knows not to try to draw too much. So it could probably do what I'm saying if somebody had wanted to do it.
But that's ok. Appreciate the info!
I found the entire system just unpredictable. I set it to only charge between 12am-6am. I don't think sitting at 100% for a few hours will hurt the battery. You can just charge to 90% as well, and then just plan the trip accordingly. My kids wanted to see the Percid (sp?) meteor showers last month, and my car was only charged to 50%, so I just swung by an EA station for 10 minutes to charge it to almost 80% to be able to make it Palomar Mountain and back. They wanted to go back the next night, so I plugged it in at home when we got back.
To explain further my point about fast and slow charging:
While the charger DOES advertise its maximum capability, its up to the charger in some cases to determine what power to deliver. I have an SMA EV Charger that collaborates with my solar panels to use excess solar energy at any point in time to charge the car. The charger will advertise to the car its capability of 10kW.
Depending on how much excess solar power is available the charger will actually charge at a rate continuously varying between 1.6kw and 10kw. When a cloud passes overhead, the charging will stop temporarily then resume when excess is again available.
The car can't predict any of this.