battery warning light issue

[frenchdave]

Dear All I am new to my s type having brought it only a few weeks ago. it is a 2005 2.7d auto 92k miles

i have had the red battery warning light come on twice in the last week, whilst driving, but after 3 or so miles it goes out again. Once home I have checked the battery and it has 12.6 volts at rest, and shows 14.2 volts with the alternator running, which makes me think that the charging system is working. Battery terminals seem tight and in good condition.

Has anyone had a similar issue and how was it resolved

many thanks

Dave

[frenchdave]

Any thoughts?

my latest fault was that when starting the battery light stayed on, and I had a reading with the engine running of 13.41 volts. After a mile of driving the light went out, and I had 14.2 volts on the battery with the engine running.

what is going on?