My daughter bought the euv about a month ago and was charging it at 8 amps.. Then it refused to charge at home and she had to keep taking it to a public charging place. Her electrician put in a new 110 line and it still won't charge at 8 amps. She changed the setting in the car to 12 Amp and now it's charging again. Why will it charge at 12 but not 8 amps?