The top of the battery should be cleaned from time to time. Dirt has a tendency to create a path for a slight short circuit between the terminals and shorting out the battery. And like I mentioned before, electrolyte levels should be checked from time to time, you shouldn't be able to see the plates sticking out above the fluid level. Those so called "maintenance-free" batteries are also serviceable more times than not. The top label can come off and there'll be the caps for the six filler holes. Sometimes they can be pried off and fluid levels can be checked/adjusted. Of course, the charging system should be up to par- no loose belts. I had a battery in my Voyager last 8 years before leaving me stranded in the middle of summer! Also, I read in another Mazda CX5 forum from a master tech (don't really know) that if you don't lock the doors the battery will drain. Don't know if any of you guys have heard this before, I sure found it odd. Something about if the car isn't locked the modules stay in standby mode therefore draining the battery, whereas if the car is locked the modules go to sleep.