I've noticed on most occasions when I start the '94 M3 with a warm engine it fails to fire-up the engine on the first attempt. First thing in the morning when the engine/battery is cold has never been a problem. I've being thinking fuel supply, spark-plugs?

today I had to crank the starter motor at least 5 or 6 times to eventually get the warm engine to start up (so I assume the battery had plenty of AmpereHours in it).

I did notice this time when I turned on the Alpine Radio it had lost all it's saved settings and stations, a sign of loss of supply voltage to the radio. So I'm now thinking the extended number of starter motor crankings had lowered the battery voltage long enough for the radio to do a power-reset.

So is the battery I've got shot or is the M3 alternator not generating the right charging voltage?

What voltage should I be seeing on the battery terminals when the alternator is charging it, 14V with close to 0 AC Volts on it?