toxsickcity:
Quality batteries should give a good 5-7 Years
That depends on how many amp-hrs are passed in and out of them, and how they are maintained. As you do not seem to have had an optimal wiring system my guess is that some of your batteries are now in poor condition.
You have told us nothing about your charge-discharge arrangements.
What specific batteries do you have?
To my mind you are chasing a Will-o'-the-wisp.
...R