Unless running a winch or other stuff, no need for deep cycle or large capacity, large CCA etc.
If running some spotties etc.
If you need much bigger battery, probably need bigger alt.
I bought an exide battery with 3 yr warranty from kmart... it lasted a year (i went and got my $ back from kmart instead of replacing it).
I have had a few cheapo batteries fail too.
I suspect it is the vibrations killing them.
Picked up a second hand optima yellow top from the wreckers for $40 (with 1 month warranty).
It's been fantastic, a new one is about $600
