Our Tesla Model 3 was briefly plugged into a 110-volt outlet in my parents' garage in Cambridge, Mass. But after about a day of charging, I received a notification on my iPhone via the Tesla app that the charging had ended. 

We turned to ace electrician Pat Flaherty, who has looked after my parents' electrical equipment for decades, to figure out what happened. His diagnosis suggests that if you are going to charge a Tesla in your garage, you should set up a separate circuit for it, lest the combination of the car and, say a garage door opener or two, might trip the breaker.

I had fun popping the front trunk from 2,000 miles away, so Pat could put the charging cables away when we determined they wouldn't be needed in the garage for the next week while we're in Denver.

The app shows that, without the charging cable attached, the car lost 5 miles of range the first day and 2 miles the second. So that's close to what the Tesla guy in Dedham had predicted--a drain of about 1 percent of the battery's range for each day it's unused and unplugged.