i am in the same boat. i actually have a fairly new battery but only 500a crank and it just wont do the job. i need something with a bit more oomph as it wont start it.
how did the varta go ?
more importantly if i had my wallet out is there anything better ? what was the AGM model ?
Maybe you should consider changing to the high HP starter to get faster cranking.
As I said, I use the Varta D15 batteries in my Pagodas and Golfs.
We also sell Varta batteries in our business and get hardly any warranty claims.
I am withdrawing my comment about the AGM battery. They have higher output but cost about double!
They are meant for the latest cars with start/stop technology.
naj