My Dad is looking at options for his Disco 3 mainly for his fridge in the cargo area. I suggested he could go with a typical dual battery set up (including isolator etc) and if necessary rewire one of his 12V sockets to run to the auxiliary battery. Another option could be a battery in a battery box in the cargo area, but not sure how he would charge it - is there any method to charge it out of the existing 12V socket (albeit from the cranking battery, but it would still need an isolator). This gives him the option of moving the battery for different applications. Any suggestions? What sort of cost is he looking at for a in-built dual battery set up (including a Traxide unit)?