I've always had a slight drain on my battery, due to clock/LCD display in 
the stereo which I measured around 90 milli-amps, tiny. When my battery got 
old/weak and I didn't drive for a week or so I had starting problems. I was 
told the 'brain' likes a certain voltage level to function properly, and the 
already depleted battery when cranking the starter wasn't putting out high 
enough volts, despite spinning the starter adequately. A new battery cured 
this, but was a cheapo that started to die after 3 months.
         A note for our Canadian viewers: DON'T EVER BUY a battery from 
Canadian Tire Corp. They are crap, I had 4 in 18 months, all replaced over 
the counter. Then I moved 1000 miles, lost the warranty card, and needed yet 
another battery which they won't give me, under the 24 month free 
replacement deal. They would like me to "keep your voice down and please 
leave since we can't help you..." (expletives deleted). Calls to corporate 
headquarters netted me zero. 
        tim s.