Tesla Motors Club
I've noticed, as many of you probably have, that when you first connect an EVSE to a Tesla with charging scheduled at a later time, the Tesla still asserts READY and ramps up to a few amps. Then it drops READY to de-energize the cable and waits for the scheduled charging time. The whole process takes maybe 30 seconds.
I hypothesize that this is to test the integrity of the connection between the car and charging cable. It's best to detect a bad connection right away so you can fix it before you go to bed and wake up with an uncharged car. If the connection between EVSE cable and car is solid, the voltage shouldn't drop much under a small load. If the voltage drops significantly, something is wrong. Flash the red light on the charge port, put a message on the dash and refuse to charge.
Even when charging is not delayed, the load is often ramped up slowly to the maximum setting (e.g. 30A, 32A or 48A). Again, this is probably to test the integrity of the EVSE/car connection, avoiding a nasty situation if it's not tight.
What do people think?
I hypothesize that this is to test the integrity of the connection between the car and charging cable. It's best to detect a bad connection right away so you can fix it before you go to bed and wake up with an uncharged car. If the connection between EVSE cable and car is solid, the voltage shouldn't drop much under a small load. If the voltage drops significantly, something is wrong. Flash the red light on the charge port, put a message on the dash and refuse to charge.
Even when charging is not delayed, the load is often ramped up slowly to the maximum setting (e.g. 30A, 32A or 48A). Again, this is probably to test the integrity of the EVSE/car connection, avoiding a nasty situation if it's not tight.
What do people think?