wokay - anyone here changed their CX8 batteries .. like, too frequently?

my last battery change was back in March 2024, from the default/original to VARTA (via bateriku). Didn't last very long (or did it? genuinely confused) - cause we had to replace it AGAIN just this morning - from VARTA to ASTRA.

Why bateriku? Becuase the nearby Mazda SC quoted 600+ to replace the battery, and that's the "cheaper" variant which "boleh tahan satu tahun" - wtf? aren't these batteries supposed to last a few years, 2-3 at least?
And the more "atas" battery is RM 725, - kuat boleh tahan 2 tahun.
Meanwhile, bateriku quoted RM468 for the ASTRA, which the abang mentioned, SHOULD last at least a year or more - and door-to-door service.

Is there something wrong with our unit (CX8), maybe the altenator? cause eating a batter every year isn't a thing we want in the long run.. car's been with us only 3 years