We've built battery boxes on the side of the engine of our 3020's and have 2 group 31 batteries on them. I would never go back to odd size batteries. Battery size is at least one thing the construction/ag/transportation industry has standardized. I just wish I could fit a 31 in my car and pickup. I can get a group 31 delivered to my door for $75.
Two 12 v batteries vs two sixes
