The E70 and likely other similar platforms suck and letting the driver know there is a charging problem. I am convinced the E70 cannot notify the driver or a charging problem, I have seen this first hand on my vehicle.
Suggest you actually use the Hidden OBC Menu to monitor the charging Voltage. Should be in the range of 13.5.-14.5 Volts. My E70 runs right around 14.0 Volts most of the time.
Or buy an UltraGauge -
UltraGauge OBDII Scan tool & Information Center
I run one of these on my E70 and have threshold alarms set to monitor Temperature and Voltage.