Battery Dead problems of the 2003 Mercedes Benz SL500

2003 Mercedes Benz sl 500. Consumer writes in regards to possible fatal flaw in vehicle. The consumer stated, as he was backing out of his driveway, he applied the brake and they failed. A red light and a sign instructed him to obtain immediate service. The mechanic, kept the vehicle for a week, but was unable to anything wrong with the brakes. At the mechanic's suggested, the vehicle was towed to the dealer. After the vehicle was there for a few days, the dealership called and said the problem was the battery had died. It was a secondary battery which supplied power to everything that consumed electricity, including the brakes in his model and year vehicle. So, if it failed, so would the brakes.