Venture Man

I have an 1987 Venture Royale and seem to replace my battery too often. Granted I do not ride it enough, so part of it is my fault. Anyway, if I were to go with a sealed battery it does not allow for my sensor. Then again what is the worst that will happen, the dummy warning will just blink all the time? I'd also like to get one soon rather than order it, so are there any common places to pick one up such as a K-Mart, Autozone, etc.?