Is this the right place to be asking about batteries? I've got a 55 plated 200SLK with a Varta 74Ah 680A battery and I think it's on its way out. I don't used the car a great deal, especially over winter so I keep the battery on a CTEK MXS 5 charger. Recently taken the car out of the garage as I needed some temporary storage space. That was about a week ago. Went to the car to move it yesterday and the battery was flat, wouldn't even turn over. What type/make of battery would you guys recommend bearing in mind that the car is used infrequently (5000 miles/year)?