I've had the EV System Warning light come on 3 times so far on my 2013 Leaf. It was after using different Level 2 charging stations (2 ClipperCreeks at different libraries and my GE Wattstation at home).
The car refuses after a while to charge any more, anywhere from 60% to 80%, and then when I turn it on to drive off I get the warning light. Shutting the car off and turning it back on clears up the light. The first two times when I was at the libraries I was messing around with the remote climate controls, so I kind of chalked it up to some kind of random glitch. But last night it was charging normally on its 2 AM to 6 AM schedule and I got the light this morning along with only 60% of a charge. I've had the car for 2 1/2 months so far.
Any idea what the problem is? I guess I'll have to call the dealership in the morning. I'll post what happens.