We never dry camp. My wife is not "outdoorsy". Don't believe me, look at the TT in my sig.
We have one 12v battery. I buy nothing but Interstates. Their warranty is second to none. The ones I just put in my truck and the one in the TT are 6 year replacement. I have had so many outlive the warranty before they died and Interstate still prorated them after the warranty. And you don't have to find an Interstate store for a warranty issue. Anywhere that sells Interstate batteries. Buy the Autozone or Napa or whoever else and you have to find one of their stores to get it covered. Not many auto parts stores where I go camping but the farm implement and gas stations with service centers always carry batteries. Many of them Interstates.