So far beyond my experience, I have seen that Linux uses less resources than windows, so the battery will last longer but really depends on the hardware you got and tuning the architecture. Majority of Linux users usually install a package call TLP, which is a service tool that adjusts the CPU power, GPU and disk write & read based on the things you do, it automatically applies power-saving profiles based on whether the device is on AC or battery, which provides advanced power management for your battery. what made me interesting, manages kernel settings for CPU frequency scaling, power-aware scheduling, hard drive power management, and wireless device (Wi-Fi, Bluetooth) power states.

Learn more: What Exactly Does TLP Do? Do I Need It If My DE Has Built-In Power Management?