That’s because he prototyped a way to use power tool batteries as an emergency source — basing his circuit on a 7812 linear regulator which got piping hot in no time flat. His next ...

That’s precisely what happened to [Larry G] when the now antiquated 7.2V NiCd batteries used by his cordless drill became too hard to track down. The drill was still in great shape and worked ...

Now, thanks to the advancement in lithium-ion battery technology and powerful compact brushless motors, the best cordless drills now wield the same kind of power as that found in older corded ...