Hi (again) Will,
The spiral wound batteries such as the one Diana points out are really very good. Their robustness and high CCA for their size are probably their best attributes, on the down side the comparable AH rating when compared to a N70 is small.
The Exide orbital has a rating of 50 AH (20 Hr rate) which is about half that of your average N70 4WD battery so keep this in mind when dimensioning your system.
A big (and often overlooked) advantage with spiral wound batteries is their fast charging capability. Where a 'normal' battery may take 6-8 hours or more to fully charge from half flat the spiral wound battery will fully charge in 1-2 hours (with a capable charging system). This can be really important when camping and moving on in short hops.
I used 66 AH Optima spiral wound batteries on the Oka for several years and they are the only batteries I have used that have lasted more than 2 years without failing due to the vibration of travelling on outback dirt roads.
I replaced the Optimas with a pair of SuperCharge marine batteries earlier this year before travelling outback including the Anne Beadell 'highway', which IMO is the worst corrugated road/track in the country, using the Optimas as my 3rd or 'house' battery. All batteries lasted the distance without failure. I think I paid about $165 each for the new SuperCharge marine batteries. Marine batteries are typically better braced internally than auto batteries making them more suited to rough terrain driving. Also they tend to be more of a 'semi' deep cycle battery which is also useful when camping/touring.
Caterpillar brand batteries are reputed to be extremely robust and very suitable for off road use but I have not used these.
Deano

Bookmarks