I have bad luck with batteries. I can get 2, maybe 2.5 years on one, but never 3 with the exception of the original Ac/Delco OEM set. Batteries, at least those considered standard and not specialized (read $$$) are what I buy as that 2 year age limitations come into play. Tried the red top's on a 6 cylinder truck, and for the premium price, they were a disappointment.
HULKMAN Alpha85S Jump Starter 2000
This is what I ordered, as reviews said it worked on larger diesel truck engines, including the older Ford 7.2 size. My 6.6 Duramax should be able to be started with it. GM does not use a isolator, so you do not know you have a problem until you go to start it and hear the dreaded 'click-click; . This product will get me where I need to go, until I can fix it, or when out in the boonies, get rolling if I am not in a group, where I can rely on another for a jump.