Makita's LXT sub-compact 18v (2.0ah) brushless DC are very small and light (2.8 lbs), the charge lasts (for my work) all day and tops off very fast. Having a second fast charge battery means you would essentially never run out of power. They accept a wide range of amp hour batteries which is a big factor in weight management. Five years ago I might have possibly thought about using an AC drill ... now, unlikely.