battery question

[mark hamster 28]

I remember when owing my E70 X5 and also especially this time of year problems about batteries not getting charged as the X5 takes a big chunk out to start the beasts, then we all have seats on and lights and heater on  ect.... so my question is...... Is it any better on the F15's now ? also is it correct to presume that when your car stops and it auto cuts out, does this mean the battery is fully or almost fully charged ??
Been quite cold lately and I'm like many love to have heated seats on gas mark 8, lights on, heater on but within about 15mins driving and some coasting, it auto switches off. No problems or anything, just wondered  O:-)

[MarkG_M3CP]

My X5 had two batteries, one of which I assumed was (somewhat at least) dedicated to starting the tractor up. I'm sure it's more complicated than that!