well you can get a better battery, i think optima or whatever, they say, have the best batteries with the longest lasting life
and just e36bimmer said, did the indicator light come on? im surprised it didnt, it SHOULD have come on because your battery only had 9 volts, which again tells me something is wrong with the wiring, unless for some odd reason it dropped 3 or 4 volts after it died..