I keep a bottle of distilled water in the garage along with a clean turkey baster for battery maintenance. I have only had to add once. I also check very very regularly for corrosion at the terminals. After suffering a while with iffy battery connections and corroded wires, I had to get a new set of cables made for my truck. On my car, it does not look like a fun process to have new cables made and I will not use clamp on cheap-O terminals you get at the parts store.

__________________
1984 300SD Orient Red/ Palomino
1989 560SEC
2016 Mazda 6 6 speed manual
1995 Ford F-150 reg cab 4.9 5speed manual