I'm certainly not an expert here, but I can say from personal experience that I switched to AA lithiums (Energizer brand) a couple of years ago. I recently pulled a few to test, and they all showed 80% of life left or better remaining! Not one of them was leaking or appeared to have any signs of impending leaks. I'm guessing I can go for a few more years safely with them in place, but I'll keep a watchful eye on them just to make sure.