OK, here's what I did, and I figure you guys will tell me I'm nuts. I happened to be in Walmart yesterday, and I noticed a display of Black and Decker 18 volt drills for $25 each. They only come with one battery, so I bought two, hoping to always have one ready in reserve, and maybe with 2 drills, they won't wear out as fast.
I don't have great expectations, these drills are made CHEAP. They don't even have a standard charger, you plug a little transformer into a jack in the drill to charge the batteries, though they are standard B&D 18 volt batteries, they do come off and would fit on a charger, but the drill with the standard charger was $64 (of course it also came with 2 batteries), but both drills seem the same. Since all of my other cordless drills never lasted more than 2 years and I paid between $150 - over $200 for each, if I get a year out of these 2, I guess I'll be satisfied. Now the question is if they're powerful enough to do the jobs I need. I'll probably get to fixing that roof over the weekend. I'll post how these cheapo drills work.
I'm usually willing to pay for decent tools, but I have never been able to find a decent cordless drill, so I'm giving using disposable cheapos drills a try.