Then check this out.
I have several Black & Decker 18 volt batteries, part #244760-00, that were at least 5 years old and only 1 good one. I decided to try and find a cheaper alternative to the 35-45 dollar new battery price. I just happened to be at Harbor Freight one day and noticed there line of 18 volt cordless power tools. The battery they use is Drill Master part # 67029, and is only 10 dollars. I decided to just buy one, since it was cheap and took it home to do a comparison with a B & D battery. They batteries are very similar in size and the way it is wired.