Battery light

[Francie]

I've a 170 tdi fr. I'm getting a battery light warning on the dash along with number plate light warning or a tail light warning. Usually it comes on 60-70mph. If I Coast it will go back off. The car has started no problem. I've tested the battery not running&running and everything seems fine. Anyone had this issue before? Could it be the alternator starting to fail? Thanks

 

[R3k1355]

Yea could be.

If you can monitor voltage in real time you might see it dip when the light comes on.
Pretty sure the cheap OBD plug in modules and the Torque app will give Voltage