My 4+ year test results
I run dual batteries 1 in the factory location and 1 in the rear back corner
Batteries are wired in parallel and never separate
Batteries manufacturers do not match 1 Optima Blue and 1 Duracell marine
Battery sizes do not match 1 Blue Optima group 34 55AH and 1 Duracell AGM Marine group 31 105AH
I have used and been hard on this system running 2 heated blankets, fridge, and power for other needs
The Duracell was getting weak so I opted to replace it. The Blue Optima will still be used after 4+years
I run dual batteries 1 in the factory location and 1 in the rear back corner
Batteries are wired in parallel and never separate
Batteries manufacturers do not match 1 Optima Blue and 1 Duracell marine
Battery sizes do not match 1 Blue Optima group 34 55AH and 1 Duracell AGM Marine group 31 105AH
I have used and been hard on this system running 2 heated blankets, fridge, and power for other needs
The Duracell was getting weak so I opted to replace it. The Blue Optima will still be used after 4+years