I know, I know.... you can buy a battery for $49.95 at Wally World, but when you lack the knowledge and tools to keep alive the memory of the various computers, it's not a bargain. It's no fun to learn that the battery replacement now makes the car run terrible, the trasmission shifts funny, the radio presets are gone, the sunroof doesn't close, the alarm goes crazy, ect, ect....Plus, how much time will it take to find someone to drive you to Wally World, buy a battery, find the tools, and then go back to the disabled vehicle and install it? A couple of hours? Time is money.

With regards to the tipping, it all depends on the situation. I just bought a new key fob transmitter for my '97 Eldorado. The dealer, cheerfully offered to program it, on the spot, with no wait. It took them about thirty minutes to get the car and the new key fob to like each other. When they were done, they insisted that there was no charge. I pulled the tech to one side and slipped him a $20.00 bill, because I wanted to, not because I felt obligated. Even if they had charged me, I would have still tipped the guy. He even showed me that I could program my own seat adjustments, climate control setting, and radio settings to work with the transmitter. That way, when my wife borrows it, I don't have to spend ten minutes putting the car back the way I left it. It's a ten year old car, and they know I do most all of my own work, they had nothing to gain by such royal treatment.