battery issue

Hi All,

I have a vauxhall vivaro, 2006. the battery light has come on intermittently, taken it to a garage. they could not find what was wrong, just got an OBD11 connector, connected it, these are the results:

connection: 12 volts
start up: 9 volts
driving: 14 volts
battery light comes on: drops to 12 volts
battery light goes off: 14 volts

any help much appreciated.