Battery life may refer to (1) the time a single charge lasts (and you can extend that by lowering power consumption), or (2) the time you can use the battery until it needs replacement (a.k.a. Battery lifespan or lifetime).
It is not clear to me which of the two you were referring to.

Battery life

The point you are asking about is so specific that I doubt you would find any statement that answers your question.
But you can readily answer it yourself by measuring power consumption under the two conditions you mean to compare, and assessing whether there is any (meaningful) difference.
There are many alternatives, including powertop, powerstat, powerapi, s-tui, and Intel Power Gadget.

Going beyond your specific question, there are many other actions you can take to save battery life (e.g. this).

Battery lifespan

One important point to extend battery lifespan of Li-ion batteries is to avoid having it for a long time at 100% or 0% charge.
For that sake, there are several options (with tlp being a popular one, in particular for Battery charge thresholds), depending on your system.

Related:

1. https://askubuntu.com/a/1313524/226614