My Optima yellow top died after 3.5 years (no longer starting the car unless the engine has been running for at least 45 mins prior) - likely from running my Taurus and aux thermofans without the engine running for at least 20 mins recently, probably never fully recovered - so bought an Exide N50 4WD battery (70Ah, 620CCA, 140RC). It's an inch taller than my Optima so I'm making a new battery tray for it to sit lower in the same spot.
Ready for test fit:
I hear most get 5-7 years from them so I may put it on a multistage charger and have it as an under bonnet aux. Already got a diesel battery tray lined up for the opposite side.
Also picking up a pair of used 180Ah AGM batteries for free from a workmate this weekend. Been designing a rear drawer system to make room for one and my fridge and plan to run a CTEK D250S Dual DC-DC charger with it.
Busy days ahead to get it all ready for Camp Coffs in Coffs Harbour NSW over Easter. 6.5 hr drive from Sydney and they had over 180 jeeps last year