I don't know what your purpose is, but you might want to look into the new LiIon cordless tools that are just coming out. They are far less bulky than the NiMH tools that have been available over the last 10-15 years. From Bosch you can get 10.8V drills that weigh about 2lbs. and have no bulky external battery pack at all, or a more traditional-style 36V drill that weighs about 6lbs. I'm sure other manufacturers have similar ones.