Best AGM battery?

[JKnight]

Originally Posted by SLO_Z28

What specifically went wrong? How do you know they're bad?

I spent too long selling to the public, and 98% + of people have no idea what they're doing. I would also venture to say that 75% + of techs dont know what theyre doing either. Its funny having a "master tech" not know what RMS is....

How do I know they're bad? The batteries didn't have enough voltage to satisfy the ECM's voltage requirements while cranking. Engine would turn over slowly and ecm would never supply any fuel (7.3l PS diesel).

In both cases the Optima's would slowly lose their ability to take a charge while the vehicle is driven and when taken to an approved Optima dealer, they test the batteries and proclaim that they have a "dead cell". Since they were under warranty and in my daily driver, I didn't do any diagnosis or attempted recharging (with a non-optima-approved charger) on my own.