No, I don't worry about tracking it that closely. If I'm interested, I just note the time when I unplug and again when I plug in. There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details.
This should answer most, if not all, of your battery questions:
I just bought a new battery to my Mac and wanted to see how well it performs.
I always forget to look at the time, that's why I need an app for that.
Thanks!