Fifty miles from home after an 8-day road trip, our Mercedes, with 205,000 miles on it, displays the red message: Alternator/Battery: Get Service. My wife looks in Yelp for the nearest place that can fix a Mercedes. She calls and gets a helpful young woman who immediately puts on Ken to ask excellent questions: "Is the steering okay? Yes, then it isn't a broken belt. Probably safe to drive here."When we arrive, we are greeted by the helpful and friendly Ken. Unfortunately it is nearly 5:00 and he can't get an alternator until morning. We ask where to get a hotel. After some talk, he suggests that he can charge the battery for half an hour and then we can drive home. Of course we have to turn off the air conditioning.After half an hour Ken tells us the battery is charged. I reach for my credit card, and he says there is no charge. Someday, he says, we can do a favor for someone in our situation. OMG!Big contrast with our local service station which gave us a hard sell about having them replace the alternator, and charged us $15 for a half-hour charge the next morning so we could get to the dealership.