I got one of these a while back
http://www.whitworths.com.au/main_it...=123&item=4190
You can get them a bit cheaper if you hunt around,
To drop a 100 ah deep cycle battery in it would be about $210
if i remember right and it did fit as I recall , the 80ah was $180,works fine though the webbing on the strap is plenty strong the plastic buckle is hopeless , I wrapped a thick leather belt around it .
cheers graham