I purchased my 2009 Lexus new. It has 23,000 miles on it.

What is your question?

I had the oil changed yesterday at the Lexus dealership. They checked the car out and told me that the battery test failed and that I should replace the battery. Is it common to have to replace a battery after only 23,000 miles? I purchased an extended warranty for the vehicle but I don't know if it covers a battery.