Unless you maxed/fixed the CPU Frequency - your CPU won't run at same voltage at all time. It can while running heavy applications - but that's just it, your power profile (if at least - Balanced) - will constantly mess with the voltage (and frequencies) - mostly lowering them, but also increasing them - depending on what you do on your system. Your particular CPU is caped at 1.4V - which triggers at (close) to max frequencies. But something tells me - it rarely does - cause of thermal throttling (lowering voltage/frequencies - while reaching a high enough temp). Thus, -80 out of -700 & up-to 1.3 V is what? 8%? A 8% bonus on battery life - sounds nice, right? Wrong. Since your CPU has TDP of 55 W - which it will rarely reach (again, cause of thermal throttling) - while your GPU (you didn't mention which - yet this is the most power hungry component in your laptop) - might be able to go as high as 80W (if a RTX 3060). The display (again, depends - which type - what refresh rate is running at - or the brightness setting) - could also use around 10 W (on average), while between 2 - 10 is needed for the SSD. That being said, don't think you'll notice much of a difrence - in terms of battery life - but it can help lowering temps a bit.
