ith batteries there is always the compromise to make between size and weight of the batteries versus performance obtained or lost.
I run "Moneypit" on a 70ah leisure battery and my wife gets a very good range from it. She completed the first 15mile Horsham run and only lost 2 segments on the pod display..larger leisure batteries are available,but they weigh more.
Car batteries seem to provide good ranges ,usually between 7-12 miles, and are lighter. But you would need to carry two to equal or better the range of the 70ah leisure battery, and that would weigh more.
All down to personal choice at the end of the day
If you've got serious cash to splash, Li-ion batteries are an option...