I'm hitting the Linux Mint forums for such because each distro may differ. Linux has a lot of options on install so I can't guess your choices. You may be running services you don't need. That's the usual drain.
https://www.google.com/search?q=Increase+battery+time+on+Linux+Mint&gl=US finds priors if you don't want to be chided about repeating an old question.
here I'm using linux mint and windows 10 on my lenovo 320s as dual boot. Highest battery backup I get from windows 10 is about 8 hours while only 3.5 hours I get from linux. ( and I do not use nVidia graphics card)
Could you please suggest me on how to improve my battery backup on linux mint?