I have this unit and obviously it is a decent age now but still running well.

I swapped out the little SSD for a proper one and I run W10 and Mint 20 in dual boot (both installed on the SSD).

I wasn't getting very good battery life so I bought, what I thought was, a like-for-like OEM replacement battery. The new one was arguably worse than the old one and would go full charge to critical over night with the laptop completely shut down. I'm pretty sure that was faulty so bought another (Green Cell this time).

Now I get, from completely charged to automatically turning off, max 1h45. That was with nothing running at all, just powered on (in Mint 20).

I've run the diagnostics in the bios and all seemed well.

I know when it was new the battery would last maybe 6 hours or so. What should I expect with these newer OSs?