I put a little motorcycle battery in mine, a Odyssey PC680. Its an AGM type like an Optima. I hasnt let me down at all but I do use the car most days and live in a temperate climate. If you live in a really cold climate or only use the car on weekends a tiny battery like this might not be the best fit.
You could also go the lithium battery route but they are a lot more expensive. I also have concerns about fire safety as they do require special chargers but in a car you're stuck with the factory charging system.
If you go for the PC680 I made a mount/adapter to use in the 2022+ GR86/BRZ:
I was watching a video on Larry Chen's GR86 build and saw his antigravity battery which reminded me that I had a brand new Odyssey PC680 I picked up for another car but didn't use. I decided to take the PC680 for my GR86 and design an adapter so I could use the stock battery strap/tie down. The...
www.gr86.org
