heres the deal went to start the car today and wouldn't even crank, nor the lights turn on or anything, so thought it was a little suspicious b/c i had driven it the day before, anyways, took out the battery and went down to autozone to get it tested just to make sure it wasn't my terminals or anything, and sure enough the battery was too dead to even test, heres were it gets fishy the old battery had 900 cold cranky amps b/c i have a ford 302 but the biggest battery they had that fit my battery tray was 750cca, which i didn't think was that big of a deal because i have no ac, stereo, or accessories. Anyway, fired up fine and then while driving down the road it slowly started to die, i could rev the engine a liitle and restarted it 2 or 3 times down the road but still insisted on coasting, luckly made it infront of my dorm and went to restart and now nothing, lights work so battery has something left, and cranks (i dont know how ,much longer) but no turnover, so is this all coincidence or is all related, is the problem the new lesser battery, old alternator, old starter, or more serious a problem? help fast