You have misconseption (spell) of what a diesel battery is , No such thing..
You are tallking about a higher output battery, there all 12 volt's just different amp, and amp hour rattings, so you dont need to put a bigger size battery in, just one with more power rating should be ok.. Unless your running loads of ice too.. in which case a higher output alternator should be priority ..
Hope this helps without getting to techy..