I use a Bosch drill-driver set (this one Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or ). Even though they are only 12V, they are plenty powerful. Their size makes makes them more comfortable to use than my Ryobi 18V, they also fit into more tight spots (say, inside a cabinet carcase) than the Ryobi. I have also had a number of battery issues with the Ryobi due to my letting the charge get too low. You can resurrect these batteries but its a PITA. I don't do production runs of drilling hundreds of holes or driving dozens of screws normally, but the battery life is extraordinary for my use case. And the Bosch battery electronics seems to tolerate low voltage conditions better than the Ryobi (again, bad habits on my part, but the system works well for me).