I am on a T480, battery life feels OK,
is tlp still a tool to use these days, or is it something from the past?
There really is no consensus on this.
Some say that kernel improvements have made power management tools unnecessary.
However, I find that tlp makes a very noticeable difference in my battery life, the latest 1.3 version has improved it further.
Others have good success using powertop.
There is no magic potion to battery life 
Good luck and let us know if you try any and how they work out for you.
Thought about that now some days, I will not change anything, at least, not now
What I see from docs, the only interesting option from tlp could be to set a battery load threshold, but for this to be useful I need a second power supply (for the place where I use to sit using battery)