Comment by Kirby64

3.6V is considered the nominal voltage, certainly not the low end cut off.

3.0V is considered basically the highest voltage. Most chemistries suggest even lower, 2.8, or even 2.5 in some situations assuming you can control the cutoff carefully. Perfectly safe to do so. You only start to have issues when you’re south of 2.5 without a load.

Most advanced battery usages let the cells drop even below that during heavy load.