c350 battery flat

Hello everyone. I have just bought a used Mercedes-Benz c350 e plug-in hybrid. After being fully charged it shows range of 13-14 miles but while using it in the E mode the range quickly reduces and finishes in 4-5 miles or so. Is something wrong with my battery? Or someone else experiencing...

My C350 AMG Sports is about 4 1/2 years old. I don't use the car very much as I am now retired, but the battery keeps going flat. I have previously had 5 Mercedes cars and never a battery has let me down, but this car seems to have a problem, the dealership told me to use the car more often but...

I got this car 4 years ago, but do not do a high mileage, currently the C350 has only done 16,500 miles, I only do around 3,000 miles a year. Last year in August 2013 the car would not start, I have extended Warranty with Mercedes, so they took the car to Chichester and replaced the battery...