Good luck. I am having the same problems. On optima #3. I keep killing cells. Seems every 6 months it gets soo low it wont recharge. Somehow, this one was able to be recharged. I even found it draining with the battery disconnected, but not enough it wont start the truck. I found my charge wire was badly corroded inside the insulation. Replaced it, and I THINK its better, but I really cant tell.
Let me know what you find. I really would love it if I didnt hear a click every time I let my truck sit for 3 days.