Southern Comfort, Did the plates get exposed due to lack of water? If so, that portion of them may be toast. Don't let it happen again, on these or succeeding batteries. If it's too difficult to easily check and fill your current
batteries, you might consider zero maintenance
ones such as AGM
or gel batteries. See other forums
(fori?) for details. You can buy an inexpensive battery capacity tester at Harbor Freight to check them under load (cool tool to have, anyway). It will give you an idea, at least, if there is sufficient life remaining in your current
bank. Everyone needs to screw up before truly learning
something new, at least the mortals among us. BTW, the putrid stench is largely the sulfides on the plates or in the electrolyte. It's just part of the joy of lead-acid batteries. At least, they don't burst into flames like some computer batteries.