When you lengthened them did you make sure you had them the right way?
I'm with Jerry on this one. I only use my rig for wheelin. That means the only time the battery see's use it's in stupid places.
It's one thing that I don't want to chance and always use a good battery.
Optima did have some bad batches for a couple years, but the last couple I've ran have been good. But I'm not sold on putting the Blue Tops in a standar vehicle.