The manufacturer VARTA provides lots of information
about their products. If someone have a question
about batteries he/she should check this page. But
I have not found an answer about the very often
discussed question:

'How to connect an auxiliary battery to my camper?'

But you will find information about mechanical and
electrical sizes of batteries and some interesting
press releases of VARTA.

http://www.varta.de/

(also available in English, same address)

Helmut
'80 Camper