3 years now. I was thinking why should the battery and the necessary equipment for caravanning be in the caravan. There is good space in the spare well, just plug into the caravan like the 240v at a caravan park.Welcome Rick,
Yes, the spare wheel well is a generous size, capable of 'hiding' a battery under the spare wheel. I have done so myself with my previous Touareg.
How long have you had your Touareg for?
What sort of duties are you considering using the 2nd battery for?