My vote is for the 31 Lifeline in parallel.
AGM batteries always render higher CCA qualities than standard flooded of the same group size.
Add that to the fact that the Lifeline has the highest rating for 100 hour discharge and the plates are twice as thick and it adds up to an almost no brainer.
Whom else makes their battery from case to lead paste in the USA? Deka will not respond to me to the answer. Even the lowly spiral batteries now come from Mexico.
Read the online LIFELINE USER MANUAL and obey it.
Charging is simple. 2 group 29 Lifelines XT batteries hold 100 USABLE amp hours. A simple Megawatt charger adjusted to 14.4 volts with a tiny screwdriver can recharge them "good enough" in four hours to endure a 3 month trip without a total charge. To total charge, get to an overnight power plug then plug the battery in at night and disconnect it in the morning. Can't get any simpler than that.
