Hello,
I suspect that a lot was written already here about batteries. New are coming daily.
While leaving in USA I used DIEHARD batteries. They performed well in my diesel Jetta in daily use. But in 1987 Westy they didn't last. I removed the battery usually for winter storage and trickle charged. In no more than 3 years the battery would fail. I recall  that the first, original VARTA battery failed on the second year.
Now I am determined to get the best battery for my Westy, price doesn't matter. The battery must fit into its compartment under the front passenger seat. What are the maximum dimensions of the battery one can comfortably put in and get out?

Many Westy owners do use auxiliary batteries. I used DIEHARD batteries. Not with great success. Can anyone suggest the best battery?
I had my batteries in the compartment under the Westy's rear seat. I would like to hear suggestions about alternative aux. battery location.

Thanks, Ark