I have a Dewalt 12V cordless drill that I have been using and it has
always worked fine for what I do.

However, recently the battery pack is lasting shorter and shorter (I
have two) and I think I would need to get new ones or have them
reconditioned.

But one thing I noticed is that with the battery lasting a shorter
time, it seems to be losing the torque as well, in other words, I am
getting trouble with putting in 2-1/2" long screw (or extracting them)
when I did not have any trouble before. �It seems that even with a
short live battery fully charged, the torque is reduced, or may be
it's just me hallucinating after breathing in too much fiber glass
insulation.

The other thing I found is that the old studs that are in my 35 year
old house, they are A LOT harder than the new studs I get at Home
Depot. �When I sister a piece of new 2x4 to an old 2x4, the screw cuts
through the new wood like butter and when it hits the old wood, it
slows down. �Same thing with cutting, I can notch new wood with a saw
much easier than the old wood. �It seems the old wood is almost as
hard if not harder than today's PT wood.



http://primecell.com/pctools.htm

they do a excellent job with cell far better than the original ones
when they were new.

very affordable too

as to wood hardness..... old wood is super dry whch probably makes it
harder.

lus old wood grew slower, the growth rings were close together, the
wood stronger than the tree farms of today, where the trees grow super
fast