So, I've got the camper with the dual battery setup, but the original VW 
battery under the driver's seat is dead.  A couple of people on the list 
have suggested that I put a marine/deep cycle battery in its place for 
powering such devices as a thermoelectric cooler.  However, when I went 
to a Pep Boys today, the guy selling batteries said that such batteries 
have to be recharged differently and that the alternator in the vanagon 
wouldn't charge the deep cycle battery properly.

Any battery experts out there who can tell me whether the deep cycle 
battery is ok?  Is its main advantage that it can power the appliances  
longer (in ADDITION to its ability to handle being discharged 
repeatedly)? 

Thanks
david 
'87 camper