I've got an 03 diesel A-Class and lately the battery has been giving me trouble. I have had to jump start it twice in the last few weeks after relatively short periods of not driving it. As far as I know the battery has never been changed.

I think the alternator is OK because when I rev it the voltage goes up on my tester.

If I buy a new battery do you think I will be able to rely on it starting? I'm very aware that winter is coming and really don't want to have to worry every Monday morning.

I looked at Halfords and it shows these three batteries as being suitable. I'm guessing that the various types go up in quality with price. Is it worth going for silver or should I go with my instinct and go for calcium?