I went on a job where I needed cordless screwdrivers about 200' from the nearest outlet, and I needed them to last me all day. I went to HF to buy some extra batteries, but the batteries were only $2.00 cheaper than buying the whole unit, battery, screwdriver and all. I bought six of them, at only 16 bucks each. Now I never have to wait for a charge because the other five are charging while I am using the first.