Voltmeter reading

[AHy3@domain.elided]

Hello all

Mike - you touched on a subject in a recent message (reproduced below) which 
I need to sort on my car - is the below the 'norm' for the stag voltmeter- is 
there an easy way to tell whether the battery is on the way out or the 
alternator (or both!!)

......''Closely investigate the battery voltage, then if less than 12 volts 
with
the engine stationary suspect the battery.  If 13.8 volts approx with
engine running''.......

Thanks 

Alan Hymers