Is a 70Ah battery overkill for a Corolla or should I upgrade?

[actonpendarves]

My battery died again this morning and I've decided to stop messing about with cheap replacements that only last a year. I've been reading that a higher capacity battery might handle the heat better, but I don't want to go too big and mess with the charging system. A mate sent me a Best Varta 70Ah car battery buying guide in Dubai and it explained how to match capacity to your car rather than just buying the biggest one on the shelf, which was actually pretty useful. But I'd still like to hear from people who've upsized or stuck with the standard spec. Did a 70Ah actually last longer in the summer or did it just cost more for no real benefit? And does it affect anything with the car's electronics if the capacity is higher than what came from the factory?