Yes, CAT 175-4370 (100AH) or Supercharge Alrounder 120AH is the way to go.
The dual battery tray is nice but does not actually give you any extra AH capacity for running your fridge and is a considerably more expensive setup.
If you need more than 120AH then you have the rear bins which will both fit another 120AH battery each of the same case size.
CAT are available from William Adams in Clayton for ~$179 inc GST.
Just make sure you take a good digital multimeter with you when you buy any battery of course to check it hasn't been sitting around for a year.
Cheers
Simon
Cheers
Simon
2003 D2a TD5, ACE, SLS, Vienna Green.
Bookmarks