Problems with battery & touch screen (after 15.6 update)

My Battery drains much faster since updating to 15.6. At what % of battery health should it be replaced? How often do people replace batteries?

*I’m trying to see if it’s an update “issue” & will be fixed on next update, or if I should just replace the battery now?*

Also, the touchscreen is “acting” differently - Almost like there is a delay.. And sometimes, it won’t respond to/recognize touch at all.. *It’s not because of a screen protector*