As a Dealer who sells at least a thousand Interstates every year (24/27/31 series), I would say it is YOUR fault. Interstate has the BEST batteries on the market. To go thru as many as you have and this is a common customer reaction, is to blame Interstate. I RARELY find that the battery to be the problem. If we can get the RV'er to come in with his RV, we almost always find the problem in the charging system of his RV or his tow vehicle charging system, causing the batteries to draw down too many cycles or never getting a full charge. I have not seen any problem with the 24 or 27 series deep cycle batteries by Interstate. Doug
