My wife's corsa always has issues on cold mornings. Never wants to start. Its recently had a alternator replaced because the bearing when on it and now I think the batteries playing up So I want to replace it. The exciting one is 12V 55ah 255a. All the ones am finding out Car Battery | Quality Car Batteries For All Cars | Cheap Car Battery are coming up 40ah 43ah and 52ah. So my question is if I put a lower AH (not sure what that is) does it make a difference?