Hi, congrats on your new to yo D200, it's an excellent camera.
The D200 was my main workhorse camera for 2 years, and I never had an issue with batteries. I always had extras, but when you're used to shooting with a D1 series camera, anything was an improvement.
You can turn down LCD brightness, the length of time the display stays on after review, that kind of thing. The battery life isn't atrocious, it's just not as good as the current cameras for reasons that have already been stated above. IIRC, you should still get 400-500 shots per charge.