I haven’t paid for a battery on my RX-8 in years. This is not because my battery is great, just the opposite. The dealer has replaced it under warranty, I think, 5 times now because it never outlasts the 2 year warranty. The car will take longer and longer to turn over until finally, one day, it will crank but not turn over and the battery gives out for trying.
The starter coils were replaced a year ago along with the battery, and just last month, I had to have them replace the battery again. They spent almost 3 days trying to find some leak in the system that is bleeding off the battery, but no luck. So, they just gave me another warranty replacement. Lather, rinse, repeat.
The OEM battery specification is for 520 CCA. I’m wondering if I need more amps. The AAA guy who jumped me last suggested that this one is underpowered. My dad got a bigger battery for his RX-8 and it starts easily, but said he had to get a saw and trim the case down to fit in its spot. I don’t want to go there myself.
The RX-8 Club had a bewildering number of opinions on battery choices, but I’m not even sure if that’s the answer.