When I need to get a new battery it will definitely be a Sears Platinum/Odyssey though. They're easier to get a hold of and their Deep Cycle.
BTW: two batteries is 106 lbs vs 75 lbs.
When you get down to the "brass tacks" of lead-acid batteries, the ampacity is directly related to the lead and acid content, which is where the weight is. I have seen "group 24" batteries differ in weight by a large amount, and their true amp-hour capacities are equally different. Your 75 lbs of lead-acid battery will never be the same amp-hour rating as 106 lbs of lead-acid battery.
Deep cycle batteries are designed for slow but deep discharge and recharge. Standard car batteries are designed for quick bursts of power, but dont like deep discharges. Using deep cycles for a vehicle or using a car battery for deep cycles can shorten their lives. But...if you use a pair of deep cycles in parallel, the short bursts of power are split between the two batteries and will retain their standard lifespan.
Whatever you do, dont by batteries from Walmart, unless you are willing to rely heavily on their warranty. I own an RV Service business and I see more dead Walmart batteries than all other brands combined.
