So a few weeks ago the stock battery on my '01 325i gives up the ghost and I get a replacement Duralast. I have the Autodrone idjits run a battery & charge test on my car and all seems well - alt is pumping out +/- 14 v's...self-diagnostic on the OBC confirms this. All is well until last week when I hit it hard on the highway and all of a sudden my batter/alternator indicator lights up - power steering is cool so I know it's prob not a belt breakdown - so I head on home. I take it back to Autodrone and they charge the battery - but the batt/alt light is still on. OBC diagnostic reveals alt is kicking out only +/- 12 volts, so I order a replacement Bosch from Pelican. I switch over to my backup BMW coupe and have been driving this all week. Yesterday I go to check my 01 and the battery is completely dead...put the batt on a trickle charge and hook it up last night and start it...batt/alt light is OFF and OBC states alt is kicking out +/- 14 volts with a full load (AC, heated seats, lights, etc). Could it be there was a short somewhere that I mistakenly remedied when I took out/replaced the batt or is it just the alternator being lazy and working when it wants to?