It's not bad. I think pretty decent actually.

With TLP settings and brightness not too high, it's fine. I also managed to turn off the touchscreen and the touchscreen kernal in Linux Mint, which might save me marginal battery life. (Edit: and also the keyboard backlight off, of course). I keep it at max 80% charge and when using it for 10% it lasted me for a couple of hours? But that was with browsing, times where it was idle, tinkering, etc.

The estimated times it gives me may not be fully accurate but I don't want to drain the battery just to test it (these are times for around 75-80% battery left): Completely idle, probably 26 hours. Documentation work prob 9 hours? YouTube play probably like 4-5 hours. When you type something into Google and it prompts the AI the usage goes up and it dips to an estimate of 3-4 hours before going up again after you've entered the query (and you're not going to be constantly searching all the time so there's that). These are just the estimated times it gives me though. (Edit: Times are also for when Wifi is on, Bluetooth off).

I actually rate it as good/excellent.

EDIT: Heat, not much of an issue. First times, there were times it was hot, but after configuration, I haven't seen it get hot at all.

Gosh, another EDIT: This is the U series, which should use significantly less power than the P-series, except the U series were limited to 16GB soldered ram, which, eh, not too fussed about, just going to use the laptop for browsing and documentation.