This is what’s important. If you don’t enable power saving in some fashion, your hardware will always be “on” at full specs. Even if the machine isn’t actually being used, it’s still powering everything to be ready to jump at any opportunity to process something quickly without ramping down.
TLP has pretty excellent default settings. Simply turning it on will likely make your battery life go 2-3x longer than without it being on, and you will have about 80% of the performance from a UX perspective. And if you want to crunch numbers faster on battery, you can tune TLP or turn it off temporarily.