As others have said, keep the battery in the 80%-30% range. Use the `batt` CLI tool to hard limit your max charge to 80%. Sadly, if you're already down to <2hrs, this might not make sense for you. Also prevent it being exposed to very hot or cold temps (even when not in use)

I type this from an M3 Max 2023 MBP that still has 98% battery health. But admittedly it's only gone through 102 charge cycles in ~2 years.

(use `pmset -g rawbatt` to get cycle count or `system_profiler SPPowerDataType | grep -A3 'Health'` to get health and cycles)