I have had several RV's! In a Class A I replaced OEM batteries with expensive lead acid 6 volt batteries, they lasted only about a year! In the last two I have replaced the OEM batteries with Optima's! Had the Class C for 4 years before getting the 5er, Optima's still going strong! With the 5er, one of the batteries was "weak" after about 9 months, in storage with power! Replaced them again with Optima's! We are full timing now, I can not explain the difference from the battery's point of view between full timing and sitting in storage with power! Knock on wood, my Optima's are going strong! I read a lot of people here criticizing Optima's, I have had nothing but good service from Optima. I have also replaced the stock batteries in my TV! Spend the couple of extra bucks, buy Optima's they won't let you down!