I’m not trying to boost Tom’s sales, but his comment about getting the order in should be taken seriously. Batteries have a finite life. I arbitrarily replace mine at five years because I don’t feel like having surprises when we use the coach. With this summer’s heat, if your batteries are getting old and you even suspect they are nearing replacement it might be worth replacing them to save some bucks. All of mine coast about $2500 so even a 6% savings is 200 miles worth of fuel.
Nothing will drive you crazier than chasing wierd electrical problems all because one battery has failed.