Hi Geoff,
Try one of these they are well made http://www.mann-hummel.com/group/upload/doc/HBLAXUCmOK5.pdf
, you can get them from Active Air Spares in Brisnbane.
The hose size is one inch so it's plenty big enough. I've got one on my ZD30
Hi Guys, The peltier can work in reverse. You can buy a peltier kit to convert an esky into a cooler for about $20 from some of the electronics stores. Also you would have been better off using the cooler bag and ice bricks. Ive got one of those thing from dicksmiths and there pretty usless.
These are european models dumped on australia because they couldent sell them, and yes they are both starting batteries. They are not isolated from each other.