I think I need to look for blogging camper van people as I didn’t get any help about my battery dilemma. I did ask on a Facebook camper van group and a lovely man told me what all the numbers mean. So the 096 is the casing size, the cca and the ah you need the highest numbers you can afford and the longest guarantee. I had a few suggestions as to makes that were good and long-lasting so it gave me enough information to start searching myself on the internet. This appears to be the best I have found so far with ah77 and cca780 and 5 year guarantee from Amazon. It does not appear to be calcium so not sure about that aspect.
Back to searching so not a lot of reading or writing happening today.