It kind of depends on what you're doing with the drill and how often you use it. If you're a homeowner/do it yourself type, then it may not make sense to buy a new 18 volt lithium ion professional grade tool. But if you stick with cheaper models or worse, off brands, then you're probably going to continue to have the same problem with the batteries. By the way, as of a couple of years ago, there were only three companies making batteries for all the power tool manufacturers. Panasonic was the supplier for Makita and DeWalt/Black & Decker among others. There are also three main types of rechargeable batteries: the oldest is Nickel Cadmium which holds the least amount of charge but is cheapest, could develop memory (only drain to a certain point), and contains the heavy metal Cadmium, which must be disposed of properly. Next is Nickel Metal Hydride, which is what cell phone batteries used to be made of. It was an improvement over older technology as they held a longer charge but fewer of them. Now there's Lithium Ion which has no memory, is much lighter, more expensive, holds a bigger charge, and will supposedly last much longer than the other two, though they haven't been in use nearly as long. An 18 volt LIon drill usually weighs about the same as a 12v NiCad. Most come with a 15 to 60 minute charger. These are just points for comparison off the top of my head, so do more research to verify.
No matter how much you pay or how much you use them, no cordless tool will last forever because of battery failure. I imagine that the amount of research that is going into finding the next generation of battery technology is significant because the possible rewards are immense. But you almost always get what you pay for and if you stick with name brands you'll be a lot better off. You should also consider a reconditioned professional quality tool. I've bought them for years for myself and the manufacturing facilities I've run and had excellent results. You can usually get a good quality tool for the same or less than you'd pay for a new Black & Decker or Ryobi at cpotools.com and reconditionedsales.com. Find one that has a maintenance charger that will keep the battery full without wearing it out. Also, heat and cold are the enemies of rechargeables so store them somewhere they aren't exposed to extreme temperatures.
Cabinetmaker and carpenter for over 20 years. Former Black & Decker Service Center tool repairman and have managed several woodworking shops. I've used tools made by most manufacturers and believe you get what you pay for in almost all cases. Many tool comparisons are available in Fine Woodworking and Consumer Reports magazines, too.